{"description":"Trending threats, MITRE ATT\u0026CK coverage, and detection metadata — refreshed continuously.","feed_url":"https://feed.craftedsignal.io/vendors/totolink/","home_page_url":"https://feed.craftedsignal.io/","items":[{"_cs_actors":[],"_cs_cves":[{"cvss":8.8,"id":"CVE-2026-7749"}],"_cs_exploited":false,"_cs_products":["N300RH 3.2.4-B20220812"],"_cs_severities":["high"],"_cs_tags":["buffer-overflow","router","cve-2026-7749"],"_cs_type":"advisory","_cs_vendors":["Totolink"],"content_html":"\u003cp\u003eA buffer overflow vulnerability has been identified in Totolink N300RH router version 3.2.4-B20220812. The vulnerability resides in the \u003ccode\u003esetWanConfig\u003c/code\u003e function within the \u003ccode\u003e/cgi-bin/cstecgi.cgi\u003c/code\u003e file, which handles POST requests. An attacker can exploit this vulnerability by manipulating the \u003ccode\u003epriDns\u003c/code\u003e argument in a crafted POST request. The vulnerability allows for remote exploitation, meaning an attacker does not need local access to the device. Public exploits for this vulnerability are already available, increasing the risk of exploitation. This vulnerability was published on 2026-05-04.\u003c/p\u003e\n\u003ch2 id=\"attack-chain\"\u003eAttack Chain\u003c/h2\u003e\n\u003col\u003e\n\u003cli\u003eThe attacker identifies a vulnerable Totolink N300RH router running firmware version 3.2.4-B20220812.\u003c/li\u003e\n\u003cli\u003eThe attacker crafts a malicious POST request targeting the \u003ccode\u003e/cgi-bin/cstecgi.cgi\u003c/code\u003e endpoint.\u003c/li\u003e\n\u003cli\u003eWithin the POST request, the attacker includes the \u003ccode\u003epriDns\u003c/code\u003e argument with a value exceeding the buffer size.\u003c/li\u003e\n\u003cli\u003eThe \u003ccode\u003esetWanConfig\u003c/code\u003e function processes the \u003ccode\u003epriDns\u003c/code\u003e argument without proper bounds checking.\u003c/li\u003e\n\u003cli\u003eThe oversized \u003ccode\u003epriDns\u003c/code\u003e value overwrites adjacent memory on the stack, potentially including control flow data.\u003c/li\u003e\n\u003cli\u003eThe attacker gains control of the program execution flow by overwriting the return address.\u003c/li\u003e\n\u003cli\u003eThe attacker executes arbitrary code on the router, potentially gaining a shell.\u003c/li\u003e\n\u003cli\u003eThe attacker could then use the compromised router to perform lateral movement, exfiltrate data, or establish a persistent backdoor.\u003c/li\u003e\n\u003c/ol\u003e\n\u003ch2 id=\"impact\"\u003eImpact\u003c/h2\u003e\n\u003cp\u003eSuccessful exploitation of this buffer overflow vulnerability can lead to complete compromise of the Totolink N300RH router. An attacker could gain unauthorized access to the device\u0026rsquo;s configuration, intercept network traffic, or use the router as a pivot point to attack other devices on the network. Given that public exploits are available, a wide range of attackers could potentially exploit this vulnerability. The CVSS v3.1 base score is 8.8 (HIGH).\u003c/p\u003e\n\u003ch2 id=\"recommendation\"\u003eRecommendation\u003c/h2\u003e\n\u003cul\u003e\n\u003cli\u003eMonitor web server logs for POST requests to \u003ccode\u003e/cgi-bin/cstecgi.cgi\u003c/code\u003e with abnormally long \u003ccode\u003epriDns\u003c/code\u003e values to detect potential exploitation attempts using the provided Sigma rule.\u003c/li\u003e\n\u003cli\u003eImplement network intrusion detection system (NIDS) rules to detect and block malicious POST requests targeting \u003ccode\u003e/cgi-bin/cstecgi.cgi\u003c/code\u003e.\u003c/li\u003e\n\u003cli\u003eContact Totolink for a security patch or firmware update to address CVE-2026-7749.\u003c/li\u003e\n\u003c/ul\u003e\n","date_modified":"2026-05-04T10:16:01Z","date_published":"2026-05-04T10:16:01Z","id":"/briefs/2026-05-totolink-n300rh-buffer-overflow/","summary":"A buffer overflow vulnerability exists in Totolink N300RH version 3.2.4-B20220812, specifically affecting the setWanConfig function within the /cgi-bin/cstecgi.cgi file, allowing a remote attacker to exploit it by manipulating the priDns argument in a POST request.","title":"Totolink N300RH Buffer Overflow Vulnerability in setWanConfig","url":"https://feed.craftedsignal.io/briefs/2026-05-totolink-n300rh-buffer-overflow/"},{"_cs_actors":[],"_cs_cves":[{"cvss":8.8,"id":"CVE-2026-7750"}],"_cs_exploited":false,"_cs_products":["N300RH 3.2.4-B20220812"],"_cs_severities":["critical"],"_cs_tags":["buffer-overflow","router","cve","webserver"],"_cs_type":"advisory","_cs_vendors":["Totolink"],"content_html":"\u003cp\u003eA buffer overflow vulnerability, identified as CVE-2026-7750, affects Totolink N300RH router version 3.2.4-B20220812. The vulnerability resides in the \u003ccode\u003esetMacFilterRules\u003c/code\u003e function within the \u003ccode\u003e/cgi-bin/cstecgi.cgi\u003c/code\u003e file, which handles POST requests. Attackers can exploit this flaw by sending a specially crafted POST request with an overly long \u003ccode\u003emac_address\u003c/code\u003e parameter, triggering a buffer overflow. Successful exploitation allows for arbitrary code execution on the device. The vulnerability is remotely exploitable, and a public exploit is available, increasing the risk of widespread attacks. Defenders should prioritize patching or mitigating this vulnerability to prevent potential compromise of affected devices.\u003c/p\u003e\n\u003ch2 id=\"attack-chain\"\u003eAttack Chain\u003c/h2\u003e\n\u003col\u003e\n\u003cli\u003eThe attacker identifies a vulnerable Totolink N300RH router running firmware version 3.2.4-B20220812.\u003c/li\u003e\n\u003cli\u003eThe attacker crafts a malicious POST request targeting the \u003ccode\u003e/cgi-bin/cstecgi.cgi\u003c/code\u003e endpoint.\u003c/li\u003e\n\u003cli\u003eWithin the POST request, the attacker includes the \u003ccode\u003emac_address\u003c/code\u003e parameter, injecting a string longer than the buffer allocated for it.\u003c/li\u003e\n\u003cli\u003eThe \u003ccode\u003esetMacFilterRules\u003c/code\u003e function processes the POST request without proper bounds checking on the \u003ccode\u003emac_address\u003c/code\u003e argument.\u003c/li\u003e\n\u003cli\u003eThe overly long \u003ccode\u003emac_address\u003c/code\u003e value overflows the buffer, overwriting adjacent memory regions.\u003c/li\u003e\n\u003cli\u003eThe attacker carefully crafts the overflow to overwrite the return address, redirecting execution flow to attacker-controlled code.\u003c/li\u003e\n\u003cli\u003eThe injected code executes with the privileges of the web server, allowing the attacker to execute arbitrary commands.\u003c/li\u003e\n\u003cli\u003eThe attacker gains complete control over the router, potentially using it for further malicious activities such as network pivoting, data exfiltration, or denial-of-service attacks.\u003c/li\u003e\n\u003c/ol\u003e\n\u003ch2 id=\"impact\"\u003eImpact\u003c/h2\u003e\n\u003cp\u003eSuccessful exploitation of CVE-2026-7750 allows a remote attacker to execute arbitrary code on the vulnerable Totolink N300RH device. This could lead to a complete compromise of the router, allowing the attacker to control network traffic, steal sensitive information, or use the router as a bot in a larger attack. Given the public availability of the exploit, a large number of unpatched devices could be vulnerable to automated attacks, potentially impacting thousands of users.\u003c/p\u003e\n\u003ch2 id=\"recommendation\"\u003eRecommendation\u003c/h2\u003e\n\u003cul\u003e\n\u003cli\u003eApply available patches or firmware updates provided by Totolink to address CVE-2026-7750.\u003c/li\u003e\n\u003cli\u003eImplement network intrusion detection system (IDS) rules to detect and block suspicious POST requests targeting the \u003ccode\u003e/cgi-bin/cstecgi.cgi\u003c/code\u003e endpoint with excessively long \u003ccode\u003emac_address\u003c/code\u003e parameters.\u003c/li\u003e\n\u003cli\u003eDeploy the Sigma rules in this brief to your SIEM to detect exploitation attempts.\u003c/li\u003e\n\u003cli\u003eMonitor web server logs for unusual POST requests to \u003ccode\u003e/cgi-bin/cstecgi.cgi\u003c/code\u003e, focusing on requests with large \u003ccode\u003emac_address\u003c/code\u003e values.\u003c/li\u003e\n\u003c/ul\u003e\n","date_modified":"2026-05-04T10:16:01Z","date_published":"2026-05-04T10:16:01Z","id":"/briefs/2026-05-totolink-buffer-overflow/","summary":"A buffer overflow vulnerability exists in Totolink N300RH 3.2.4-B20220812 allowing remote attackers to execute arbitrary code by manipulating the mac_address argument in the setMacFilterRules function of the /cgi-bin/cstecgi.cgi POST request handler.","title":"Totolink N300RH Buffer Overflow Vulnerability (CVE-2026-7750)","url":"https://feed.craftedsignal.io/briefs/2026-05-totolink-buffer-overflow/"},{"_cs_actors":[],"_cs_cves":[{"cvss":9.8,"id":"CVE-2026-7719"}],"_cs_exploited":false,"_cs_products":["WA300 5.2cu.7112_B20190227"],"_cs_severities":["critical"],"_cs_tags":["buffer overflow","remote code execution","cve-2026-7719","totolink"],"_cs_type":"advisory","_cs_vendors":["Totolink"],"content_html":"\u003cp\u003eA critical buffer overflow vulnerability, identified as CVE-2026-7719, has been discovered in Totolink WA300 version 5.2cu.7112_B20190227. This vulnerability resides within the \u003ccode\u003eloginauth\u003c/code\u003e function of the \u003ccode\u003e/cgi-bin/cstecgi.cgi\u003c/code\u003e file, affecting the POST Request Handler component. The vulnerability is triggered by manipulating the \u003ccode\u003ehttp_host\u003c/code\u003e argument in a POST request. The exploit is publicly available, increasing the risk of widespread exploitation. This vulnerability allows for remote code execution, potentially granting attackers full control over the affected device. The affected version was released in February 2019. Defenders should prioritize patching or mitigating this vulnerability to prevent potential compromise.\u003c/p\u003e\n\u003ch2 id=\"attack-chain\"\u003eAttack Chain\u003c/h2\u003e\n\u003col\u003e\n\u003cli\u003eThe attacker identifies a vulnerable Totolink WA300 device running firmware version 5.2cu.7112_B20190227.\u003c/li\u003e\n\u003cli\u003eThe attacker crafts a malicious HTTP POST request targeting the \u003ccode\u003e/cgi-bin/cstecgi.cgi\u003c/code\u003e endpoint.\u003c/li\u003e\n\u003cli\u003eThe crafted POST request includes a specially crafted \u003ccode\u003ehttp_host\u003c/code\u003e argument designed to overflow the buffer in the \u003ccode\u003eloginauth\u003c/code\u003e function.\u003c/li\u003e\n\u003cli\u003eThe vulnerable \u003ccode\u003eloginauth\u003c/code\u003e function processes the \u003ccode\u003ehttp_host\u003c/code\u003e argument without proper bounds checking.\u003c/li\u003e\n\u003cli\u003eThe oversized \u003ccode\u003ehttp_host\u003c/code\u003e argument overwrites adjacent memory regions, including the return address on the stack.\u003c/li\u003e\n\u003cli\u003eUpon completion of the \u003ccode\u003eloginauth\u003c/code\u003e function, the overwritten return address is used, redirecting execution to attacker-controlled code.\u003c/li\u003e\n\u003cli\u003eThe attacker-controlled code executes with elevated privileges, allowing the attacker to execute arbitrary commands on the device.\u003c/li\u003e\n\u003cli\u003eThe attacker gains complete control of the device, potentially using it for malicious purposes such as botnet participation, data theft, or further network penetration.\u003c/li\u003e\n\u003c/ol\u003e\n\u003ch2 id=\"impact\"\u003eImpact\u003c/h2\u003e\n\u003cp\u003eSuccessful exploitation of CVE-2026-7719 allows a remote attacker to execute arbitrary code on the vulnerable Totolink WA300 device. This can lead to complete device compromise, allowing the attacker to steal sensitive information, use the device as a botnet node, or pivot to other devices on the network. Given the public availability of the exploit, widespread exploitation is possible, potentially affecting a large number of home and small business networks using the vulnerable device.\u003c/p\u003e\n\u003ch2 id=\"recommendation\"\u003eRecommendation\u003c/h2\u003e\n\u003cul\u003e\n\u003cli\u003eDeploy the Sigma rule \u003ccode\u003eDetect Totolink WA300 HTTP Host Buffer Overflow Attempt\u003c/code\u003e to identify exploitation attempts in web server logs.\u003c/li\u003e\n\u003cli\u003eMonitor web server logs for POST requests to \u003ccode\u003e/cgi-bin/cstecgi.cgi\u003c/code\u003e with unusually long \u003ccode\u003ehttp_host\u003c/code\u003e headers.\u003c/li\u003e\n\u003cli\u003eConsider deploying a web application firewall (WAF) rule to filter out malicious requests targeting CVE-2026-7719.\u003c/li\u003e\n\u003cli\u003eUpgrade to a patched version of the firmware or replace the affected device to remediate the vulnerability.\u003c/li\u003e\n\u003c/ul\u003e\n","date_modified":"2026-05-04T02:15:58Z","date_published":"2026-05-04T02:15:58Z","id":"/briefs/2024-01-totolink-wa300-buffer-overflow/","summary":"A buffer overflow vulnerability exists in Totolink WA300 version 5.2cu.7112_B20190227 within the loginauth function of the /cgi-bin/cstecgi.cgi file, specifically affecting the POST Request Handler component, triggerable via manipulation of the http_host argument, and remotely exploitable with a publicly available exploit.","title":"Totolink WA300 Buffer Overflow Vulnerability (CVE-2026-7719)","url":"https://feed.craftedsignal.io/briefs/2024-01-totolink-wa300-buffer-overflow/"},{"_cs_actors":[],"_cs_cves":[{"cvss":8.8,"id":"CVE-2026-7717"}],"_cs_exploited":false,"_cs_products":["WA300 5.2cu.7112_B20190227"],"_cs_severities":["critical"],"_cs_tags":["buffer-overflow","remote-code-execution","router"],"_cs_type":"threat","_cs_vendors":["Totolink"],"content_html":"\u003cp\u003eA buffer overflow vulnerability has been identified in Totolink WA300 wireless router, specifically version 5.2cu.7112_B20190227. The vulnerability resides within the \u003ccode\u003eUploadCustomModule\u003c/code\u003e function of the \u003ccode\u003e/cgi-bin/cstecgi.cgi\u003c/code\u003e file, a component of the POST Request Handler. The identified vulnerability allows a remote attacker to cause a buffer overflow through manipulation of the \u003ccode\u003eFile\u003c/code\u003e argument within a crafted POST request. Public proof-of-concept exploit code is available, increasing the likelihood of exploitation. This vulnerability poses a significant risk, as successful exploitation could lead to arbitrary code execution, potentially allowing attackers to fully compromise affected devices. Defenders should prioritize detection and mitigation strategies to prevent exploitation.\u003c/p\u003e\n\u003ch2 id=\"attack-chain\"\u003eAttack Chain\u003c/h2\u003e\n\u003col\u003e\n\u003cli\u003eAttacker identifies a vulnerable Totolink WA300 device running firmware version 5.2cu.7112_B20190227.\u003c/li\u003e\n\u003cli\u003eAttacker crafts a malicious POST request targeting the \u003ccode\u003e/cgi-bin/cstecgi.cgi\u003c/code\u003e endpoint.\u003c/li\u003e\n\u003cli\u003eThe POST request includes a \u003ccode\u003eFile\u003c/code\u003e argument with a payload exceeding the buffer size allocated for the \u003ccode\u003eUploadCustomModule\u003c/code\u003e function.\u003c/li\u003e\n\u003cli\u003eThe \u003ccode\u003eUploadCustomModule\u003c/code\u003e function processes the POST request without proper bounds checking on the \u003ccode\u003eFile\u003c/code\u003e argument.\u003c/li\u003e\n\u003cli\u003eThe oversized \u003ccode\u003eFile\u003c/code\u003e argument overwrites adjacent memory regions, including potentially critical program data and control flow instructions.\u003c/li\u003e\n\u003cli\u003eThe buffer overflow allows the attacker to inject and execute arbitrary code on the device.\u003c/li\u003e\n\u003cli\u003eThe attacker gains remote shell access to the device with elevated privileges.\u003c/li\u003e\n\u003cli\u003eThe attacker could then use the compromised device to pivot into the internal network or cause a denial-of-service condition.\u003c/li\u003e\n\u003c/ol\u003e\n\u003ch2 id=\"impact\"\u003eImpact\u003c/h2\u003e\n\u003cp\u003eSuccessful exploitation of this buffer overflow vulnerability can lead to complete compromise of the affected Totolink WA300 device. An attacker could gain unauthorized access to the device\u0026rsquo;s configuration, intercept network traffic, or use the device as a bot in a larger attack. Given the high CVSS score of 8.8, the impact is considered critical. Home and small business networks using the affected router model are at risk. The vulnerability allows for remote code execution, leading to significant potential for damage.\u003c/p\u003e\n\u003ch2 id=\"recommendation\"\u003eRecommendation\u003c/h2\u003e\n\u003cul\u003e\n\u003cli\u003eDeploy the Sigma rule \u003ccode\u003eDetect Totolink WA300 UploadCustomModule Buffer Overflow Attempt\u003c/code\u003e to detect malicious POST requests targeting the vulnerable endpoint.\u003c/li\u003e\n\u003cli\u003eMonitor web server logs for POST requests to \u003ccode\u003e/cgi-bin/cstecgi.cgi\u003c/code\u003e with unusually large \u003ccode\u003eFile\u003c/code\u003e parameters, as indicated in the Sigma rule.\u003c/li\u003e\n\u003cli\u003eApply any available firmware updates from Totolink to patch CVE-2026-7717 if they become available.\u003c/li\u003e\n\u003cli\u003eImplement network segmentation to limit the impact of a compromised router on other internal network resources.\u003c/li\u003e\n\u003c/ul\u003e\n","date_modified":"2026-05-04T01:16:05Z","date_published":"2026-05-04T01:16:05Z","id":"/briefs/2026-05-totolink-wa300-buffer-overflow/","summary":"A remote buffer overflow vulnerability exists in the UploadCustomModule function of the /cgi-bin/cstecgi.cgi file in the POST Request Handler component of Totolink WA300 version 5.2cu.7112_B20190227, which can be exploited by manipulating the File argument.","title":"Totolink WA300 Buffer Overflow Vulnerability in UploadCustomModule","url":"https://feed.craftedsignal.io/briefs/2026-05-totolink-wa300-buffer-overflow/"},{"_cs_actors":[],"_cs_cves":[{"cvss":9.8,"id":"CVE-2026-7546"}],"_cs_exploited":false,"_cs_products":["NR1800X 9.1.0u.6279_B20210910"],"_cs_severities":["critical"],"_cs_tags":["cve","remote code execution","buffer overflow","router"],"_cs_type":"advisory","_cs_vendors":["Totolink"],"content_html":"\u003cp\u003eA critical security vulnerability, CVE-2026-7546, affects Totolink NR1800X routers running firmware version 9.1.0u.6279_B20210910. The vulnerability resides within the \u003ccode\u003efind_host_ip\u003c/code\u003e function of the lighttpd web server component. By exploiting this flaw, a remote, unauthenticated attacker can trigger a stack-based buffer overflow through manipulation of the Host argument in an HTTP request. The publicly disclosed exploit allows attackers to potentially gain complete control of the device. This vulnerability poses a significant risk to home and small business networks utilizing the affected Totolink router model, as successful exploitation leads to arbitrary code execution.\u003c/p\u003e\n\u003ch2 id=\"attack-chain\"\u003eAttack Chain\u003c/h2\u003e\n\u003col\u003e\n\u003cli\u003eThe attacker identifies a vulnerable Totolink NR1800X router running firmware version 9.1.0u.6279_B20210910.\u003c/li\u003e\n\u003cli\u003eThe attacker crafts a malicious HTTP request targeting the router\u0026rsquo;s web interface.\u003c/li\u003e\n\u003cli\u003eThe crafted request includes a \u003ccode\u003eHost\u003c/code\u003e header with a string exceeding the buffer size allocated in the \u003ccode\u003efind_host_ip\u003c/code\u003e function within the \u003ccode\u003elighttpd\u003c/code\u003e component.\u003c/li\u003e\n\u003cli\u003eThe router\u0026rsquo;s \u003ccode\u003elighttpd\u003c/code\u003e server processes the HTTP request and passes the \u003ccode\u003eHost\u003c/code\u003e header value to the vulnerable function.\u003c/li\u003e\n\u003cli\u003eThe \u003ccode\u003efind_host_ip\u003c/code\u003e function attempts to store the oversized \u003ccode\u003eHost\u003c/code\u003e value in a stack-allocated buffer.\u003c/li\u003e\n\u003cli\u003eA stack-based buffer overflow occurs due to the insufficient buffer size.\u003c/li\u003e\n\u003cli\u003eThe overflow overwrites adjacent memory on the stack, potentially including the return address.\u003c/li\u003e\n\u003cli\u003eThe attacker gains arbitrary code execution on the device.\u003c/li\u003e\n\u003c/ol\u003e\n\u003ch2 id=\"impact\"\u003eImpact\u003c/h2\u003e\n\u003cp\u003eSuccessful exploitation of CVE-2026-7546 allows a remote attacker to execute arbitrary code on the vulnerable Totolink NR1800X device. This can lead to complete control of the router, allowing the attacker to modify router settings, intercept network traffic, or use the compromised router as a pivot point for further attacks within the network. Given the nature of stack-based buffer overflows, the attacker can potentially install persistent backdoors or malware. This presents a significant risk to users, potentially exposing sensitive data and infrastructure to unauthorized access.\u003c/p\u003e\n\u003ch2 id=\"recommendation\"\u003eRecommendation\u003c/h2\u003e\n\u003cul\u003e\n\u003cli\u003eApply available patches released by Totolink to remediate CVE-2026-7546.\u003c/li\u003e\n\u003cli\u003eMonitor network traffic for suspicious HTTP requests targeting Totolink routers, specifically looking for abnormally long Host headers with the Sigma rule \u0026ldquo;Detect Suspiciously Long Host Header\u0026rdquo;.\u003c/li\u003e\n\u003cli\u003eImplement network segmentation to limit the impact of a compromised router.\u003c/li\u003e\n\u003cli\u003eReview and harden router configurations, including disabling remote administration if not required.\u003c/li\u003e\n\u003c/ul\u003e\n","date_modified":"2026-05-01T03:16:01Z","date_published":"2026-05-01T03:16:01Z","id":"/briefs/2026-05-totolink-rce/","summary":"A stack-based buffer overflow vulnerability (CVE-2026-7546) in the Totolink NR1800X router allows remote attackers to achieve arbitrary code execution by sending a crafted HTTP request with a manipulated Host header to the vulnerable lighttpd component.","title":"Totolink NR1800X Stack-Based Buffer Overflow Vulnerability","url":"https://feed.craftedsignal.io/briefs/2026-05-totolink-rce/"},{"_cs_actors":[],"_cs_cves":[{"cvss":8.8,"id":"CVE-2026-7548"}],"_cs_exploited":false,"_cs_products":["NR1800X 9.1.0u.6279_B20210910"],"_cs_severities":["critical"],"_cs_tags":["command-injection","router","network"],"_cs_type":"advisory","_cs_vendors":["Totolink"],"content_html":"\u003cp\u003eA command injection vulnerability, identified as CVE-2026-7548, affects Totolink NR1800X router version 9.1.0u.6279_B20210910. The vulnerability resides within the \u003ccode\u003esub_41A68C\u003c/code\u003e function of the \u003ccode\u003e/cgi-bin/cstecgi.cgi\u003c/code\u003e file. By manipulating the \u003ccode\u003esetUssd\u003c/code\u003e argument, a remote attacker can inject arbitrary commands into the system. Publicly available exploit code makes exploitation easier. This vulnerability poses a significant risk as it allows unauthenticated remote attackers to execute arbitrary commands on the affected device, potentially leading to full system compromise.\u003c/p\u003e\n\u003ch2 id=\"attack-chain\"\u003eAttack Chain\u003c/h2\u003e\n\u003col\u003e\n\u003cli\u003eThe attacker identifies a vulnerable Totolink NR1800X device running firmware version 9.1.0u.6279_B20210910.\u003c/li\u003e\n\u003cli\u003eThe attacker sends a crafted HTTP request to the \u003ccode\u003e/cgi-bin/cstecgi.cgi\u003c/code\u003e endpoint.\u003c/li\u003e\n\u003cli\u003eThe HTTP request includes the \u003ccode\u003esetUssd\u003c/code\u003e argument with a malicious payload designed to inject a command.\u003c/li\u003e\n\u003cli\u003eThe \u003ccode\u003esub_41A68C\u003c/code\u003e function processes the \u003ccode\u003esetUssd\u003c/code\u003e argument without proper sanitization.\u003c/li\u003e\n\u003cli\u003eThe injected command is executed by the system with the privileges of the web server process.\u003c/li\u003e\n\u003cli\u003eThe attacker gains initial access and can execute arbitrary commands on the device.\u003c/li\u003e\n\u003cli\u003eThe attacker may then use the command execution to escalate privileges, install malware, or pivot to other devices on the network.\u003c/li\u003e\n\u003c/ol\u003e\n\u003ch2 id=\"impact\"\u003eImpact\u003c/h2\u003e\n\u003cp\u003eSuccessful exploitation of this vulnerability allows an attacker to execute arbitrary commands on the affected Totolink NR1800X router. This could lead to complete compromise of the device, allowing the attacker to control network traffic, modify router settings, or use the router as a pivot point to attack other devices on the network. Given the wide usage of Totolink routers, a large number of devices could be vulnerable.\u003c/p\u003e\n\u003ch2 id=\"recommendation\"\u003eRecommendation\u003c/h2\u003e\n\u003cul\u003e\n\u003cli\u003eMonitor web server logs for requests to \u003ccode\u003e/cgi-bin/cstecgi.cgi\u003c/code\u003e containing suspicious characters or command injection attempts in the \u003ccode\u003esetUssd\u003c/code\u003e parameter, using the Sigma rule provided below.\u003c/li\u003e\n\u003cli\u003eImplement rate limiting on the \u003ccode\u003e/cgi-bin/cstecgi.cgi\u003c/code\u003e endpoint to mitigate brute-force exploitation attempts.\u003c/li\u003e\n\u003cli\u003eApply available patches provided by Totolink to address the CVE-2026-7548 vulnerability.\u003c/li\u003e\n\u003cli\u003eDeploy the Sigma rule to your SIEM and tune for your environment.\u003c/li\u003e\n\u003c/ul\u003e\n","date_modified":"2026-05-01T03:16:01Z","date_published":"2026-05-01T03:16:01Z","id":"/briefs/2026-05-totolink-command-injection/","summary":"A command injection vulnerability exists in Totolink NR1800X version 9.1.0u.6279_B20210910, affecting the function sub_41A68C of the file /cgi-bin/cstecgi.cgi; by manipulating the argument setUssd, a remote attacker can inject commands, and an exploit is publicly available.","title":"Totolink NR1800X Command Injection Vulnerability","url":"https://feed.craftedsignal.io/briefs/2026-05-totolink-command-injection/"},{"_cs_actors":[],"_cs_cves":[{"cvss":9.8,"id":"CVE-2026-7241"}],"_cs_exploited":false,"_cs_products":["A8000RU"],"_cs_severities":["critical"],"_cs_tags":["cve-2026-7241","command-injection","router"],"_cs_type":"advisory","_cs_vendors":["Totolink"],"content_html":"\u003cp\u003eA critical vulnerability, CVE-2026-7241, has been identified in Totolink A8000RU router firmware version 7.1cu.643_b20200521. This vulnerability resides within the CGI Handler component, specifically in the \u003ccode\u003esetWiFiBasicCfg\u003c/code\u003e function of the \u003ccode\u003e/cgi-bin/cstecgi.cgi\u003c/code\u003e file. Successful exploitation allows a remote attacker to inject and execute arbitrary operating system commands by manipulating the \u003ccode\u003ewifiOff\u003c/code\u003e argument. The vulnerability has been publicly disclosed, increasing the risk of exploitation. This poses a significant threat to users of the affected router model, potentially leading to complete system compromise.\u003c/p\u003e\n\u003ch2 id=\"attack-chain\"\u003eAttack Chain\u003c/h2\u003e\n\u003col\u003e\n\u003cli\u003eThe attacker identifies a Totolink A8000RU router running firmware version 7.1cu.643_b20200521.\u003c/li\u003e\n\u003cli\u003eThe attacker sends a crafted HTTP request to the \u003ccode\u003e/cgi-bin/cstecgi.cgi\u003c/code\u003e endpoint.\u003c/li\u003e\n\u003cli\u003eThe HTTP request targets the \u003ccode\u003esetWiFiBasicCfg\u003c/code\u003e function.\u003c/li\u003e\n\u003cli\u003eThe attacker injects malicious OS commands into the \u003ccode\u003ewifiOff\u003c/code\u003e argument of the HTTP request.\u003c/li\u003e\n\u003cli\u003eThe CGI handler processes the request without proper sanitization of the \u003ccode\u003ewifiOff\u003c/code\u003e argument.\u003c/li\u003e\n\u003cli\u003eThe injected OS commands are executed by the system with the privileges of the web server.\u003c/li\u003e\n\u003cli\u003eThe attacker gains remote shell access or performs other malicious actions, such as modifying router settings.\u003c/li\u003e\n\u003c/ol\u003e\n\u003ch2 id=\"impact\"\u003eImpact\u003c/h2\u003e\n\u003cp\u003eSuccessful exploitation of this vulnerability allows a remote attacker to execute arbitrary operating system commands on the affected Totolink A8000RU router. This can lead to complete compromise of the device, potentially enabling the attacker to eavesdrop on network traffic, modify router configuration, or use the router as a node in a botnet. Given the widespread use of Totolink routers, a successful attack could impact numerous home and small business networks.\u003c/p\u003e\n\u003ch2 id=\"recommendation\"\u003eRecommendation\u003c/h2\u003e\n\u003cul\u003e\n\u003cli\u003eDeploy the Sigma rule \u0026ldquo;Detect Totolink A8000RU Command Injection Attempt\u0026rdquo; to your SIEM to identify exploitation attempts targeting the vulnerable endpoint.\u003c/li\u003e\n\u003cli\u003eApply the Sigma rule \u0026ldquo;Detect Suspicious CGI Request Arguments\u0026rdquo; to identify unusual commands in cgi requests.\u003c/li\u003e\n\u003cli\u003eMonitor web server logs for requests to \u003ccode\u003e/cgi-bin/cstecgi.cgi\u003c/code\u003e with suspicious characters or commands in the \u003ccode\u003ewifiOff\u003c/code\u003e parameter, as this is the attack vector described in CVE-2026-7241.\u003c/li\u003e\n\u003c/ul\u003e\n","date_modified":"2026-04-28T09:17:41Z","date_published":"2026-04-28T09:17:41Z","id":"/briefs/2026-04-totolink-rce/","summary":"Totolink A8000RU version 7.1cu.643_b20200521 is vulnerable to OS command injection via manipulation of the `wifiOff` argument in the `setWiFiBasicCfg` function of the `/cgi-bin/cstecgi.cgi` CGI handler, allowing a remote attacker to execute arbitrary commands on the system.","title":"Totolink A8000RU OS Command Injection Vulnerability","url":"https://feed.craftedsignal.io/briefs/2026-04-totolink-rce/"},{"_cs_actors":[],"_cs_cves":[{"cvss":9.8,"id":"CVE-2026-7244"}],"_cs_exploited":false,"_cs_products":["A8000RU"],"_cs_severities":["critical"],"_cs_tags":["command injection","router vulnerability","cve-2026-7244"],"_cs_type":"advisory","_cs_vendors":["Totolink"],"content_html":"\u003cp\u003eA critical security vulnerability, identified as CVE-2026-7244, has been discovered in Totolink A8000RU router firmware version 7.1cu.643_b20200521. This flaw resides within the CGI handler, specifically in the \u003ccode\u003esetWiFiEasyGuestCfg\u003c/code\u003e function located in the \u003ccode\u003e/cgi-bin/cstecgi.cgi\u003c/code\u003e file. By manipulating the \u003ccode\u003emerge\u003c/code\u003e argument, a remote attacker can inject and execute arbitrary operating system commands on the affected device. The vulnerability is remotely exploitable and a proof-of-concept exploit has been publicly released, increasing the risk of widespread exploitation. This poses a significant threat as it allows for complete control over the device, potentially leading to data breaches, network compromise, and botnet recruitment.\u003c/p\u003e\n\u003ch2 id=\"attack-chain\"\u003eAttack Chain\u003c/h2\u003e\n\u003col\u003e\n\u003cli\u003eThe attacker sends a malicious HTTP request to the \u003ccode\u003e/cgi-bin/cstecgi.cgi\u003c/code\u003e endpoint on the Totolink A8000RU router.\u003c/li\u003e\n\u003cli\u003eThe request targets the \u003ccode\u003esetWiFiEasyGuestCfg\u003c/code\u003e function.\u003c/li\u003e\n\u003cli\u003eThe attacker crafts the request to include a payload in the \u003ccode\u003emerge\u003c/code\u003e argument designed to inject an OS command.\u003c/li\u003e\n\u003cli\u003eThe \u003ccode\u003ecstecgi.cgi\u003c/code\u003e script processes the request and passes the \u003ccode\u003emerge\u003c/code\u003e argument to a system call without proper sanitization.\u003c/li\u003e\n\u003cli\u003eThe injected OS command is executed with the privileges of the web server.\u003c/li\u003e\n\u003cli\u003eThe attacker gains arbitrary code execution on the router\u0026rsquo;s operating system.\u003c/li\u003e\n\u003cli\u003eThe attacker can then install malware, change router settings, or use the router as a pivot point to attack other devices on the network.\u003c/li\u003e\n\u003c/ol\u003e\n\u003ch2 id=\"impact\"\u003eImpact\u003c/h2\u003e\n\u003cp\u003eSuccessful exploitation of CVE-2026-7244 grants an attacker complete control over the vulnerable Totolink A8000RU router. This can lead to a variety of malicious activities, including data exfiltration, denial-of-service attacks, and the installation of persistent backdoors. Given the availability of a public exploit, a large number of devices could be compromised quickly. This could result in widespread botnet infections, impacting home users and small businesses relying on these routers for network connectivity.\u003c/p\u003e\n\u003ch2 id=\"recommendation\"\u003eRecommendation\u003c/h2\u003e\n\u003cul\u003e\n\u003cli\u003eMonitor web server logs for requests to \u003ccode\u003e/cgi-bin/cstecgi.cgi\u003c/code\u003e with suspicious parameters in the query string, especially related to the \u003ccode\u003emerge\u003c/code\u003e argument to detect exploitation attempts (see rule: \u0026ldquo;Detect Totolink A8000RU Command Injection Attempt\u0026rdquo;).\u003c/li\u003e\n\u003cli\u003eImplement network intrusion detection system (NIDS) rules to identify malicious payloads being sent to the affected endpoint (see rule: \u0026ldquo;Detect Totolink A8000RU Command Injection - Network\u0026rdquo;).\u003c/li\u003e\n\u003cli\u003eApply the Sigma rule \u0026ldquo;Detect Totolink A8000RU Command Injection in Logs\u0026rdquo; to your SIEM to identify successful command injection attempts based on web server logs.\u003c/li\u003e\n\u003cli\u003eMonitor for unusual process execution originating from the web server process, indicating potential exploitation.\u003c/li\u003e\n\u003cli\u003eUnfortunately, a patch is not available so consider migrating to a more secure router.\u003c/li\u003e\n\u003c/ul\u003e\n","date_modified":"2026-04-28T09:16:17Z","date_published":"2026-04-28T09:16:17Z","id":"/briefs/2026-04-totolink-command-injection/","summary":"A critical OS command injection vulnerability (CVE-2026-7244) exists in the setWiFiEasyGuestCfg function of the /cgi-bin/cstecgi.cgi file in Totolink A8000RU version 7.1cu.643_b20200521, allowing remote attackers to execute arbitrary commands.","title":"Totolink A8000RU Command Injection Vulnerability (CVE-2026-7244)","url":"https://feed.craftedsignal.io/briefs/2026-04-totolink-command-injection/"},{"_cs_actors":[],"_cs_cves":[{"cvss":9.8,"id":"CVE-2026-7240"}],"_cs_exploited":false,"_cs_products":["A8000RU 7.1cu.643_b20200521"],"_cs_severities":["critical"],"_cs_tags":["cve-2026-7240","command-injection","totolink","router","cgi"],"_cs_type":"advisory","_cs_vendors":["Totolink"],"content_html":"\u003cp\u003eA critical vulnerability, CVE-2026-7240, has been identified in Totolink A8000RU router firmware version 7.1cu.643_b20200521. This flaw resides within the CGI Handler component, specifically in the \u003ccode\u003esetVpnAccountCfg\u003c/code\u003e function of the \u003ccode\u003e/cgi-bin/cstecgi.cgi\u003c/code\u003e file. By exploiting this vulnerability, a remote attacker can inject arbitrary operating system commands by manipulating the \u003ccode\u003eUser\u003c/code\u003e argument. Publicly available exploit code exists, increasing the risk of widespread exploitation. This vulnerability poses a significant threat as it allows complete control of the affected device, potentially leading to network compromise and data exfiltration.\u003c/p\u003e\n\u003ch2 id=\"attack-chain\"\u003eAttack Chain\u003c/h2\u003e\n\u003col\u003e\n\u003cli\u003eThe attacker identifies a Totolink A8000RU router running firmware version 7.1cu.643_b20200521 accessible via the web interface.\u003c/li\u003e\n\u003cli\u003eThe attacker crafts a malicious HTTP request targeting the \u003ccode\u003e/cgi-bin/cstecgi.cgi\u003c/code\u003e endpoint.\u003c/li\u003e\n\u003cli\u003eThe crafted request includes the \u003ccode\u003esetVpnAccountCfg\u003c/code\u003e function call with a payload injected into the \u003ccode\u003eUser\u003c/code\u003e argument. The payload contains OS commands to be executed on the router.\u003c/li\u003e\n\u003cli\u003eThe router\u0026rsquo;s CGI Handler processes the request without proper sanitization of the \u003ccode\u003eUser\u003c/code\u003e argument.\u003c/li\u003e\n\u003cli\u003eThe injected OS commands are executed with the privileges of the web server process.\u003c/li\u003e\n\u003cli\u003eThe attacker gains remote shell access to the router.\u003c/li\u003e\n\u003cli\u003eThe attacker leverages the compromised router to pivot within the network, potentially accessing sensitive data or other internal systems.\u003c/li\u003e\n\u003cli\u003eThe attacker could modify the router\u0026rsquo;s configuration, intercept network traffic, or use it as a launching point for further attacks.\u003c/li\u003e\n\u003c/ol\u003e\n\u003ch2 id=\"impact\"\u003eImpact\u003c/h2\u003e\n\u003cp\u003eSuccessful exploitation of CVE-2026-7240 allows a remote, unauthenticated attacker to execute arbitrary commands on the affected Totolink A8000RU router. This could lead to a complete compromise of the device, potentially exposing sensitive information, enabling unauthorized network access, and facilitating further attacks within the network. Given the ease of exploitation and the availability of public exploits, organizations using this router model are at high risk of experiencing significant security breaches.\u003c/p\u003e\n\u003ch2 id=\"recommendation\"\u003eRecommendation\u003c/h2\u003e\n\u003cul\u003e\n\u003cli\u003eDeploy the Sigma rule \u003ccode\u003eDetect Totolink A8000RU Command Injection Attempt\u003c/code\u003e to identify exploitation attempts against vulnerable Totolink routers. Enable webserver logging to capture the necessary request data.\u003c/li\u003e\n\u003cli\u003eApply the Sigma rule \u003ccode\u003eDetect Totolink A8000RU Malicious User Agent\u003c/code\u003e to detect potential exploit attempts based on modified User-Agent headers.\u003c/li\u003e\n\u003cli\u003eMonitor webserver logs for requests to \u003ccode\u003e/cgi-bin/cstecgi.cgi\u003c/code\u003e containing suspicious characters or command sequences in the \u003ccode\u003ecs-uri-query\u003c/code\u003e field, indicative of command injection attempts.\u003c/li\u003e\n\u003cli\u003eGiven the public availability of exploit code, organizations using the Totolink A8000RU 7.1cu.643_b20200521 are advised to replace the device if a patch is not available from the vendor.\u003c/li\u003e\n\u003c/ul\u003e\n","date_modified":"2026-04-28T08:16:02Z","date_published":"2026-04-28T08:16:02Z","id":"/briefs/2026-04-totolink-cmd-injection/","summary":"CVE-2026-7240 is a critical OS command injection vulnerability in the Totolink A8000RU router that allows remote attackers to execute arbitrary commands by manipulating the 'User' argument in the 'setVpnAccountCfg' function.","title":"Totolink A8000RU OS Command Injection Vulnerability (CVE-2026-7240)","url":"https://feed.craftedsignal.io/briefs/2026-04-totolink-cmd-injection/"},{"_cs_actors":[],"_cs_cves":[{"cvss":7.2,"id":"CVE-2026-7219"}],"_cs_exploited":false,"_cs_products":["N300RT"],"_cs_severities":["high"],"_cs_tags":["buffer-overflow","iot","router","cve-2026-7219"],"_cs_type":"advisory","_cs_vendors":["Totolink"],"content_html":"\u003cp\u003eA buffer overflow vulnerability, identified as CVE-2026-7219, has been discovered in Totolink N300RT router firmware version 3.4.0-B20250430. The vulnerability resides within the \u003ccode\u003e/boafrm/formIpQoS\u003c/code\u003e file and is triggered by manipulating the \u003ccode\u003eentry_name\u003c/code\u003e argument. An attacker can exploit this flaw remotely to potentially execute arbitrary code on the device. Publicly available exploit code exists, increasing the risk of exploitation. This vulnerability poses a significant threat to devices running the affected firmware, potentially allowing attackers to gain unauthorized access and control over the router.\u003c/p\u003e\n\u003ch2 id=\"attack-chain\"\u003eAttack Chain\u003c/h2\u003e\n\u003col\u003e\n\u003cli\u003eAn attacker identifies a Totolink N300RT device running firmware version 3.4.0-B20250430.\u003c/li\u003e\n\u003cli\u003eThe attacker crafts a malicious HTTP request targeting the \u003ccode\u003e/boafrm/formIpQoS\u003c/code\u003e file.\u003c/li\u003e\n\u003cli\u003eThe crafted request includes a payload designed to overflow the buffer associated with the \u003ccode\u003eentry_name\u003c/code\u003e argument.\u003c/li\u003e\n\u003cli\u003eThe router\u0026rsquo;s web server processes the malicious request, leading to a buffer overflow condition.\u003c/li\u003e\n\u003cli\u003eThe attacker overwrites adjacent memory regions, potentially including return addresses or other critical data.\u003c/li\u003e\n\u003cli\u003eUpon function return, the overwritten return address is used, diverting execution flow to attacker-controlled code.\u003c/li\u003e\n\u003cli\u003eThe attacker gains arbitrary code execution on the device.\u003c/li\u003e\n\u003cli\u003eThe attacker can then use this access to modify router settings, intercept network traffic, or establish a persistent backdoor.\u003c/li\u003e\n\u003c/ol\u003e\n\u003ch2 id=\"impact\"\u003eImpact\u003c/h2\u003e\n\u003cp\u003eSuccessful exploitation of this vulnerability allows a remote attacker to execute arbitrary code on the Totolink N300RT device. This could lead to complete compromise of the router, enabling attackers to monitor network traffic, change DNS settings, or use the device as part of a botnet. Given the number of Totolink N300RT devices deployed, this vulnerability could have a widespread impact, especially for home and small business users.\u003c/p\u003e\n\u003ch2 id=\"recommendation\"\u003eRecommendation\u003c/h2\u003e\n\u003cul\u003e\n\u003cli\u003eMonitor web server logs for requests targeting \u003ccode\u003e/boafrm/formIpQoS\u003c/code\u003e with unusually long \u003ccode\u003eentry_name\u003c/code\u003e parameters to detect potential exploitation attempts. Implement the Sigma rule \u003ccode\u003eDetect Suspicious Totolink FormIpQoS Requests\u003c/code\u003e.\u003c/li\u003e\n\u003cli\u003eApply firmware updates as soon as they are released by Totolink to patch CVE-2026-7219.\u003c/li\u003e\n\u003cli\u003eImplement network segmentation to limit the impact of a compromised router on other devices on the network.\u003c/li\u003e\n\u003cli\u003eConsider using a web application firewall (WAF) to filter out malicious requests targeting the router\u0026rsquo;s web interface and activate the \u003ccode\u003eDetect Large POST Requests to Router Config Pages\u003c/code\u003e Sigma rule.\u003c/li\u003e\n\u003c/ul\u003e\n","date_modified":"2026-04-28T04:16:23Z","date_published":"2026-04-28T04:16:23Z","id":"/briefs/2026-04-totolink-n300rt-bo/","summary":"A remote buffer overflow vulnerability exists in Totolink N300RT 3.4.0-B20250430 via manipulation of the 'entry_name' argument in the /boafrm/formIpQoS file, potentially leading to arbitrary code execution.","title":"Totolink N300RT Buffer Overflow Vulnerability (CVE-2026-7219)","url":"https://feed.craftedsignal.io/briefs/2026-04-totolink-n300rt-bo/"},{"_cs_actors":[],"_cs_cves":[{"cvss":9.8,"id":"CVE-2026-7154"}],"_cs_exploited":true,"_cs_products":["A8000RU 7.1cu.643_b20200521"],"_cs_severities":["critical"],"_cs_tags":["cve-2026-7154","command-injection","network-device"],"_cs_type":"threat","_cs_vendors":["Totolink"],"content_html":"\u003cp\u003eCVE-2026-7154 describes a critical vulnerability affecting the Totolink A8000RU router, specifically version 7.1cu.643_b20200521. The vulnerability is located in the \u003ccode\u003esetAdvancedInfoShow\u003c/code\u003e function within the \u003ccode\u003e/cgi-bin/cstecgi.cgi\u003c/code\u003e file, which handles CGI requests. An attacker can remotely exploit this flaw by manipulating the \u003ccode\u003etty_server\u003c/code\u003e argument, leading to OS command injection. This means an unauthenticated attacker can potentially execute arbitrary commands on the underlying operating system of the router. The exploit is publicly available, increasing the likelihood of exploitation in the wild. Successful exploitation allows complete control over the device.\u003c/p\u003e\n\u003ch2 id=\"attack-chain\"\u003eAttack Chain\u003c/h2\u003e\n\u003col\u003e\n\u003cli\u003eThe attacker identifies a vulnerable Totolink A8000RU router with the affected firmware version exposed to the internet.\u003c/li\u003e\n\u003cli\u003eThe attacker crafts a malicious HTTP POST request targeting the \u003ccode\u003e/cgi-bin/cstecgi.cgi\u003c/code\u003e endpoint.\u003c/li\u003e\n\u003cli\u003eThe crafted request includes the \u003ccode\u003esetAdvancedInfoShow\u003c/code\u003e function call with a manipulated \u003ccode\u003etty_server\u003c/code\u003e argument containing an OS command injection payload.\u003c/li\u003e\n\u003cli\u003eThe webserver receives the crafted request and passes the \u003ccode\u003etty_server\u003c/code\u003e argument to the vulnerable function.\u003c/li\u003e\n\u003cli\u003eThe vulnerable function executes the attacker-supplied OS command due to insufficient input validation and sanitization.\u003c/li\u003e\n\u003cli\u003eThe injected command executes with the privileges of the web server process, typically root.\u003c/li\u003e\n\u003cli\u003eThe attacker gains arbitrary code execution on the router\u0026rsquo;s operating system.\u003c/li\u003e\n\u003cli\u003eThe attacker can then use this access to install malware, change router settings, or use the router as a pivot point for further attacks within the network.\u003c/li\u003e\n\u003c/ol\u003e\n\u003ch2 id=\"impact\"\u003eImpact\u003c/h2\u003e\n\u003cp\u003eSuccessful exploitation of CVE-2026-7154 allows a remote, unauthenticated attacker to execute arbitrary commands on the affected Totolink A8000RU router. This can lead to complete compromise of the device, potentially affecting all connected devices on the network. An attacker could steal sensitive information, disrupt network services, or use the compromised router as a botnet node. Given the public availability of the exploit, mass exploitation is a significant risk.\u003c/p\u003e\n\u003ch2 id=\"recommendation\"\u003eRecommendation\u003c/h2\u003e\n\u003cul\u003e\n\u003cli\u003eMonitor web server logs for suspicious POST requests to \u003ccode\u003e/cgi-bin/cstecgi.cgi\u003c/code\u003e with unusual characters or command-like syntax in the \u003ccode\u003etty_server\u003c/code\u003e parameter, as this could indicate exploitation attempts (see example Sigma rule below).\u003c/li\u003e\n\u003cli\u003eImplement network intrusion detection system (IDS) rules to detect attempts to exploit this vulnerability by monitoring HTTP traffic for malicious payloads in the \u003ccode\u003etty_server\u003c/code\u003e parameter.\u003c/li\u003e\n\u003cli\u003eApply available patches or firmware updates provided by Totolink to address CVE-2026-7154 when they become available.\u003c/li\u003e\n\u003c/ul\u003e\n","date_modified":"2024-01-23T12:00:00Z","date_published":"2024-01-23T12:00:00Z","id":"/briefs/2024-01-totolink-a8000ru-command-injection/","summary":"A remote OS command injection vulnerability exists in the Totolink A8000RU router version 7.1cu.643_b20200521, allowing attackers to execute arbitrary commands by manipulating the 'tty_server' argument in the 'setAdvancedInfoShow' function.","title":"Totolink A8000RU OS Command Injection Vulnerability (CVE-2026-7154)","url":"https://feed.craftedsignal.io/briefs/2024-01-totolink-a8000ru-command-injection/"},{"_cs_actors":[],"_cs_cves":[{"cvss":9.8,"id":"CVE-2026-7538"}],"_cs_exploited":false,"_cs_products":["A8000RU 7.1cu.643_b20200521"],"_cs_severities":["critical"],"_cs_tags":["command-injection","rce","totolink"],"_cs_type":"advisory","_cs_vendors":["Totolink"],"content_html":"\u003cp\u003eA critical vulnerability, tracked as CVE-2026-7538, has been identified in Totolink A8000RU router firmware version 7.1cu.643_b20200521. This vulnerability resides within the CGI handler component, specifically in the \u003ccode\u003e/cgi-bin/cstecgi.cgi\u003c/code\u003e file. The vulnerability arises from improper handling of the \u003ccode\u003eproto\u003c/code\u003e argument, which can be manipulated by an attacker to inject arbitrary operating system commands. Given that the attack can be initiated remotely and a public exploit is available, defenders should prioritize patching or implementing mitigations immediately. Exploitation could allow unauthenticated attackers to gain complete control over the affected device.\u003c/p\u003e\n\u003ch2 id=\"attack-chain\"\u003eAttack Chain\u003c/h2\u003e\n\u003col\u003e\n\u003cli\u003eAn attacker identifies a Totolink A8000RU router with the vulnerable firmware version (7.1cu.643_b20200521) exposed to the internet.\u003c/li\u003e\n\u003cli\u003eThe attacker sends a specially crafted HTTP request to the \u003ccode\u003e/cgi-bin/cstecgi.cgi\u003c/code\u003e endpoint.\u003c/li\u003e\n\u003cli\u003eThe HTTP request includes a malicious payload within the \u003ccode\u003eproto\u003c/code\u003e argument. This payload is designed to execute arbitrary OS commands.\u003c/li\u003e\n\u003cli\u003eThe CGI handler processes the request without proper sanitization of the \u003ccode\u003eproto\u003c/code\u003e argument.\u003c/li\u003e\n\u003cli\u003eThe unsanitized input from the \u003ccode\u003eproto\u003c/code\u003e argument is passed directly to a system call, resulting in OS command injection.\u003c/li\u003e\n\u003cli\u003eThe injected command executes with the privileges of the web server process.\u003c/li\u003e\n\u003cli\u003eThe attacker gains the ability to execute arbitrary code on the router, potentially including downloading and executing a reverse shell.\u003c/li\u003e\n\u003cli\u003eThe attacker establishes a persistent foothold and can perform further malicious activities, such as network reconnaissance, data exfiltration, or using the compromised device as part of a botnet.\u003c/li\u003e\n\u003c/ol\u003e\n\u003ch2 id=\"impact\"\u003eImpact\u003c/h2\u003e\n\u003cp\u003eSuccessful exploitation of CVE-2026-7538 grants attackers complete control over the affected Totolink A8000RU router. This can lead to a variety of malicious outcomes, including unauthorized access to the local network, data theft, and the use of the router as a node in a botnet for DDoS attacks or other malicious campaigns. Given the availability of a public exploit, widespread exploitation is possible if devices are not promptly patched or protected.\u003c/p\u003e\n\u003ch2 id=\"recommendation\"\u003eRecommendation\u003c/h2\u003e\n\u003cul\u003e\n\u003cli\u003eApply available patches or firmware updates for Totolink A8000RU version 7.1cu.643_b20200521 to remediate CVE-2026-7538.\u003c/li\u003e\n\u003cli\u003eImplement network intrusion detection system (IDS) rules to detect malicious HTTP requests targeting the \u003ccode\u003e/cgi-bin/cstecgi.cgi\u003c/code\u003e endpoint with suspicious payloads in the \u003ccode\u003eproto\u003c/code\u003e argument.\u003c/li\u003e\n\u003cli\u003eDeploy the Sigma rule \u003ccode\u003eDetect Totolink A8000RU Command Injection Attempt\u003c/code\u003e to your SIEM to identify exploitation attempts based on suspicious HTTP requests.\u003c/li\u003e\n\u003cli\u003eMonitor web server logs for unusual activity or errors related to the \u003ccode\u003e/cgi-bin/cstecgi.cgi\u003c/code\u003e endpoint.\u003c/li\u003e\n\u003c/ul\u003e\n","date_modified":"2024-01-03T12:00:00Z","date_published":"2024-01-03T12:00:00Z","id":"/briefs/2024-01-totolink-a8000ru-rce/","summary":"A remote OS command injection vulnerability exists in Totolink A8000RU version 7.1cu.643_b20200521 via manipulation of the 'proto' argument in the /cgi-bin/cstecgi.cgi CGI handler, potentially leading to complete system compromise.","title":"Totolink A8000RU OS Command Injection Vulnerability","url":"https://feed.craftedsignal.io/briefs/2024-01-totolink-a8000ru-rce/"}],"language":"en","title":"CraftedSignal Threat Feed — Totolink","version":"https://jsonfeed.org/version/1.1"}