{"description":"Trending threats, MITRE ATT\u0026CK coverage, and detection metadata — refreshed continuously.","feed_url":"https://feed.craftedsignal.io/tags/totolink/","home_page_url":"https://feed.craftedsignal.io/","items":[{"_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":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":8.8,"id":"CVE-2026-6194"}],"_cs_exploited":false,"_cs_products":[],"_cs_severities":["critical"],"_cs_tags":["cve-2026-6194","buffer-overflow","totolink","router"],"_cs_type":"advisory","_cs_vendors":[],"content_html":"\u003cp\u003eCVE-2026-6194 describes a stack-based buffer overflow vulnerability present in Totolink A3002MU router firmware version B20211125.1046. The vulnerability resides within the HTTP Request Handler, specifically in the \u003ccode\u003esub_410188\u003c/code\u003e function of the \u003ccode\u003e/boafrm/formWlanSetup\u003c/code\u003e file. A remote attacker can exploit this vulnerability by crafting a malicious HTTP request that manipulates the \u003ccode\u003ewan-url\u003c/code\u003e argument, leading to arbitrary code execution on the device. Publicly available exploit code increases the likelihood of exploitation. Successful exploitation allows an attacker to compromise the device and potentially gain control of the network.\u003c/p\u003e\n\u003ch2 id=\"attack-chain\"\u003eAttack Chain\u003c/h2\u003e\n\u003col\u003e\n\u003cli\u003eThe attacker identifies a vulnerable Totolink A3002MU router running firmware B20211125.1046.\u003c/li\u003e\n\u003cli\u003eThe attacker crafts a malicious HTTP POST request targeting the \u003ccode\u003e/boafrm/formWlanSetup\u003c/code\u003e endpoint.\u003c/li\u003e\n\u003cli\u003eThe crafted request includes a \u003ccode\u003ewan-url\u003c/code\u003e argument with a payload exceeding the buffer size allocated for it in the \u003ccode\u003esub_410188\u003c/code\u003e function.\u003c/li\u003e\n\u003cli\u003eThe HTTP Request Handler processes the request and calls the vulnerable \u003ccode\u003esub_410188\u003c/code\u003e function.\u003c/li\u003e\n\u003cli\u003eDue to insufficient bounds checking, the oversized \u003ccode\u003ewan-url\u003c/code\u003e argument overflows the stack buffer.\u003c/li\u003e\n\u003cli\u003eThe attacker overwrites critical data on the stack, including the return address.\u003c/li\u003e\n\u003cli\u003eUpon returning from the \u003ccode\u003esub_410188\u003c/code\u003e function, execution is redirected to an attacker-controlled address.\u003c/li\u003e\n\u003cli\u003eThe attacker executes arbitrary code, potentially gaining full control of the router.\u003c/li\u003e\n\u003c/ol\u003e\n\u003ch2 id=\"impact\"\u003eImpact\u003c/h2\u003e\n\u003cp\u003eSuccessful exploitation of CVE-2026-6194 can lead to complete compromise of the affected Totolink A3002MU router. This allows attackers to eavesdrop on network traffic, modify DNS settings, inject malicious code into web pages served to connected clients, or use the compromised router as a botnet node. Given the widespread use of these routers, a large number of devices could be at risk, potentially impacting home and small business networks.\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/boafrm/formWlanSetup\u003c/code\u003e with unusually long \u003ccode\u003ewan-url\u003c/code\u003e parameters to detect potential exploitation attempts (see Sigma rule \u0026ldquo;Detect Suspicious WAN-URL Parameter Length\u0026rdquo;).\u003c/li\u003e\n\u003cli\u003eDeploy the Sigma rules provided in this brief to your SIEM to detect and alert on potential exploitation attempts.\u003c/li\u003e\n\u003cli\u003eIf possible, block requests matching the patterns identified in the Sigma rules at your network perimeter.\u003c/li\u003e\n\u003c/ul\u003e\n","date_modified":"2026-04-14T12:00:00Z","date_published":"2026-04-14T12:00:00Z","id":"/briefs/2026-04-totolink-a3002mu-bo/","summary":"A stack-based buffer overflow vulnerability (CVE-2026-6194) exists in the Totolink A3002MU B20211125.1046 router firmware, specifically affecting the `/boafrm/formWlanSetup` component's HTTP request handler, which allows remote attackers to execute arbitrary code by manipulating the `wan-url` argument.","title":"Totolink A3002MU Router Stack-Based Buffer Overflow Vulnerability","url":"https://feed.craftedsignal.io/briefs/2026-04-totolink-a3002mu-bo/"},{"_cs_actors":[],"_cs_cves":[{"cvss":8.8,"id":"CVE-2026-6168"}],"_cs_exploited":false,"_cs_products":[],"_cs_severities":["critical"],"_cs_tags":["totolink","buffer-overflow","cve-2026-6168","router"],"_cs_type":"advisory","_cs_vendors":[],"content_html":"\u003cp\u003eA stack-based buffer overflow vulnerability, tracked as CVE-2026-6168, has been identified in TOTOLINK A7000R routers with firmware versions up to 9.1.0u.6115. The vulnerability resides within the \u003ccode\u003esetWiFiEasyGuestCfg\u003c/code\u003e function located in the \u003ccode\u003e/cgi-bin/cstecgi.cgi\u003c/code\u003e file. Successful exploitation allows a remote attacker to execute arbitrary code on the device. Publicly available exploit code exists, increasing the risk of widespread exploitation. Given the widespread use of TOTOLINK devices, this vulnerability poses a significant threat to home and small business networks. Exploitation is possible with low privileges, as it only requires authentication to the device\u0026rsquo;s web interface.\u003c/p\u003e\n\u003ch2 id=\"attack-chain\"\u003eAttack Chain\u003c/h2\u003e\n\u003col\u003e\n\u003cli\u003eAttacker authenticates to the TOTOLINK A7000R web interface. This step assumes default credentials or compromised credentials.\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 request includes the \u003ccode\u003esetWiFiEasyGuestCfg\u003c/code\u003e function call.\u003c/li\u003e\n\u003cli\u003eThe \u003ccode\u003essid5g\u003c/code\u003e argument within the POST request is populated with a string exceeding the buffer\u0026rsquo;s capacity.\u003c/li\u003e\n\u003cli\u003eThe vulnerable \u003ccode\u003esetWiFiEasyGuestCfg\u003c/code\u003e function in \u003ccode\u003e/cgi-bin/cstecgi.cgi\u003c/code\u003e processes the oversized \u003ccode\u003essid5g\u003c/code\u003e argument without proper bounds checking.\u003c/li\u003e\n\u003cli\u003eThis leads to a stack-based buffer overflow, overwriting adjacent memory regions.\u003c/li\u003e\n\u003cli\u003eThe attacker leverages the overflow to inject and execute arbitrary code on the device.\u003c/li\u003e\n\u003cli\u003eSuccessful code execution can grant the attacker full control of the router, enabling further malicious activities.\u003c/li\u003e\n\u003c/ol\u003e\n\u003ch2 id=\"impact\"\u003eImpact\u003c/h2\u003e\n\u003cp\u003eSuccessful exploitation of CVE-2026-6168 allows a remote attacker to execute arbitrary code on the vulnerable TOTOLINK A7000R device. This can lead to complete compromise of the router, including the ability to intercept network traffic, modify DNS settings, inject malicious scripts into websites, and use the router as a pivot point for further attacks within the network. This vulnerability affects potentially thousands of devices, particularly in home and small business environments.\u003c/p\u003e\n\u003ch2 id=\"recommendation\"\u003eRecommendation\u003c/h2\u003e\n\u003cul\u003e\n\u003cli\u003eApply firmware updates immediately if TOTOLINK releases a patch for CVE-2026-6168.\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\u003essid5g\u003c/code\u003e parameters, using the provided Sigma rule.\u003c/li\u003e\n\u003cli\u003eImplement network intrusion detection systems (IDS) rules to detect attempts to exploit stack-based buffer overflows targeting TOTOLINK devices.\u003c/li\u003e\n\u003cli\u003eRestrict access to the router\u0026rsquo;s web interface to trusted IP addresses, if possible.\u003c/li\u003e\n\u003cli\u003eEnforce strong and unique passwords for all router accounts.\u003c/li\u003e\n\u003c/ul\u003e\n","date_modified":"2026-04-13T07:16:51Z","date_published":"2026-04-13T07:16:51Z","id":"/briefs/2026-04-totolink-buffer-overflow/","summary":"A stack-based buffer overflow vulnerability (CVE-2026-6168) exists in TOTOLINK A7000R devices up to version 9.1.0u.6115, allowing remote attackers to execute arbitrary code via a crafted ssid5g argument to the setWiFiEasyGuestCfg function in /cgi-bin/cstecgi.cgi.","title":"TOTOLINK A7000R Stack-Based Buffer Overflow Vulnerability","url":"https://feed.craftedsignal.io/briefs/2026-04-totolink-buffer-overflow/"},{"_cs_actors":[],"_cs_cves":[{"cvss":7.3,"id":"CVE-2026-5676"}],"_cs_exploited":false,"_cs_products":[],"_cs_severities":["high"],"_cs_tags":["cve-2026-5676","authentication-bypass","totolink"],"_cs_type":"advisory","_cs_vendors":[],"content_html":"\u003cp\u003eCVE-2026-5676 is an authentication bypass vulnerability affecting Totolink A8000R routers with firmware version 5.9c.681_B20180413. The vulnerability resides in the \u003ccode\u003e/cgi-bin/cstecgi.cgi\u003c/code\u003e file, specifically within the \u003ccode\u003esetLanguageCfg\u003c/code\u003e function. By manipulating the \u003ccode\u003elangType\u003c/code\u003e argument, an attacker can bypass authentication checks, potentially gaining unauthorized access to sensitive router functionalities. This vulnerability can be exploited remotely without requiring any prior authentication. A public exploit is available, increasing the likelihood of exploitation. Defenders should prioritize detection and patching of this vulnerability to prevent unauthorized access and control of affected devices.\u003c/p\u003e\n\u003ch2 id=\"attack-chain\"\u003eAttack Chain\u003c/h2\u003e\n\u003col\u003e\n\u003cli\u003eAn attacker identifies a vulnerable Totolink A8000R router running firmware 5.9c.681_B20180413.\u003c/li\u003e\n\u003cli\u003eThe attacker sends a crafted HTTP request to \u003ccode\u003e/cgi-bin/cstecgi.cgi\u003c/code\u003e.\u003c/li\u003e\n\u003cli\u003eThe request targets the \u003ccode\u003esetLanguageCfg\u003c/code\u003e function.\u003c/li\u003e\n\u003cli\u003eThe request includes a manipulated \u003ccode\u003elangType\u003c/code\u003e argument designed to bypass authentication.\u003c/li\u003e\n\u003cli\u003eThe vulnerable \u003ccode\u003esetLanguageCfg\u003c/code\u003e function processes the request without proper authentication checks.\u003c/li\u003e\n\u003cli\u003eThe attacker gains unauthorized access to router configuration settings.\u003c/li\u003e\n\u003cli\u003eThe attacker modifies sensitive settings such as DNS, routing rules, or firewall configuration.\u003c/li\u003e\n\u003cli\u003eThe attacker achieves full control of the router, potentially using it for malicious purposes like eavesdropping, traffic redirection, or botnet activities.\u003c/li\u003e\n\u003c/ol\u003e\n\u003ch2 id=\"impact\"\u003eImpact\u003c/h2\u003e\n\u003cp\u003eSuccessful exploitation of CVE-2026-5676 allows a remote, unauthenticated attacker to gain full control of the affected Totolink A8000R router. This can lead to a variety of malicious activities, including unauthorized access to the local network, data theft, DNS hijacking, and the use of the router as part of a botnet. The potential number of affected devices is substantial, as the A8000R model is widely used.\u003c/p\u003e\n\u003ch2 id=\"recommendation\"\u003eRecommendation\u003c/h2\u003e\n\u003cul\u003e\n\u003cli\u003eDeploy the Sigma rule to detect malicious HTTP requests targeting the vulnerable \u003ccode\u003esetLanguageCfg\u003c/code\u003e function (see \u0026ldquo;Detect Totolink A8000R Authentication Bypass Attempt\u0026rdquo; rule below).\u003c/li\u003e\n\u003cli\u003eMonitor web server logs for requests to \u003ccode\u003e/cgi-bin/cstecgi.cgi\u003c/code\u003e with unusual \u003ccode\u003elangType\u003c/code\u003e parameters (see \u0026ldquo;Detect Totolink A8000R Authentication Bypass Attempt\u0026rdquo; rule below).\u003c/li\u003e\n\u003cli\u003eUpgrade the firmware of Totolink A8000R routers to a patched version that addresses CVE-2026-5676 (consult the vendor\u0026rsquo;s website for updates).\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\u003c/ul\u003e\n","date_modified":"2026-04-06T19:16:30Z","date_published":"2026-04-06T19:16:30Z","id":"/briefs/2026-04-totolink-auth-bypass/","summary":"A remote, unauthenticated attacker can bypass authentication on Totolink A8000R routers running firmware version 5.9c.681_B20180413 by manipulating the `langType` argument in the `setLanguageCfg` function of the `/cgi-bin/cstecgi.cgi` file.","title":"Totolink A8000R Authentication Bypass Vulnerability (CVE-2026-5676)","url":"https://feed.craftedsignal.io/briefs/2026-04-totolink-auth-bypass/"},{"_cs_actors":[],"_cs_cves":[{"cvss":7.3,"id":"CVE-2026-5677"}],"_cs_exploited":false,"_cs_products":[],"_cs_severities":["high"],"_cs_tags":["cve-2026-5677","totolink","command-injection","network-device"],"_cs_type":"advisory","_cs_vendors":[],"content_html":"\u003cp\u003eA critical OS command injection vulnerability, tracked as CVE-2026-5677, has been identified in Totolink A7100RU routers running firmware version 7.4cu.2313_b20191024. The vulnerability resides within the \u003ccode\u003eCsteSystem\u003c/code\u003e function of the \u003ccode\u003e/cgi-bin/cstecgi.cgi\u003c/code\u003e file. By manipulating the \u003ccode\u003eresetFlags\u003c/code\u003e argument, a remote attacker can inject and execute arbitrary operating system commands on the affected device. This exploit is publicly available, increasing the risk of widespread exploitation. Successful exploitation allows an attacker to gain complete control over the device, potentially leading to data theft, denial of service, or use of the router as part of a botnet.\u003c/p\u003e\n\u003ch2 id=\"attack-chain\"\u003eAttack Chain\u003c/h2\u003e\n\u003col\u003e\n\u003cli\u003eThe attacker identifies a vulnerable Totolink A7100RU router with firmware version 7.4cu.2313_b20191024.\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\u003eresetFlags\u003c/code\u003e argument with a malicious payload containing OS commands.\u003c/li\u003e\n\u003cli\u003eThe \u003ccode\u003eCsteSystem\u003c/code\u003e function processes the request without proper sanitization of the \u003ccode\u003eresetFlags\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 arbitrary code execution on the router\u0026rsquo;s operating system.\u003c/li\u003e\n\u003cli\u003eThe attacker can then install persistent backdoors, modify router settings, or use the device for further attacks.\u003c/li\u003e\n\u003c/ol\u003e\n\u003ch2 id=\"impact\"\u003eImpact\u003c/h2\u003e\n\u003cp\u003eSuccessful exploitation of CVE-2026-5677 allows a remote attacker to execute arbitrary commands on vulnerable Totolink A7100RU routers. This can lead to complete compromise of the device, enabling attackers to steal sensitive information, disrupt network services, or use the router as a launchpad for other attacks, such as botnet participation or man-in-the-middle attacks. Given the widespread use of Totolink routers, a successful large-scale exploitation could affect thousands of users.\u003c/p\u003e\n\u003ch2 id=\"recommendation\"\u003eRecommendation\u003c/h2\u003e\n\u003cul\u003e\n\u003cli\u003eDeploy the Sigma rule \u003ccode\u003eDetect Totolink A7100RU CsteSystem Command Injection Attempt\u003c/code\u003e to your SIEM to identify malicious requests to the \u003ccode\u003e/cgi-bin/cstecgi.cgi\u003c/code\u003e endpoint.\u003c/li\u003e\n\u003cli\u003eInspect web server logs for suspicious POST requests to \u003ccode\u003e/cgi-bin/cstecgi.cgi\u003c/code\u003e containing shell metacharacters in the \u003ccode\u003eresetFlags\u003c/code\u003e parameter to detect exploitation attempts (webserver logs).\u003c/li\u003e\n\u003c/ul\u003e\n","date_modified":"2026-04-06T19:16:30Z","date_published":"2026-04-06T19:16:30Z","id":"/briefs/2026-04-totolink-os-command-injection/","summary":"A remote OS command injection vulnerability (CVE-2026-5677) exists in the CsteSystem function of the /cgi-bin/cstecgi.cgi file in Totolink A7100RU firmware version 7.4cu.2313_b20191024 due to improper handling of the resetFlags argument.","title":"Totolink A7100RU OS Command Injection Vulnerability (CVE-2026-5677)","url":"https://feed.craftedsignal.io/briefs/2026-04-totolink-os-command-injection/"},{"_cs_actors":[],"_cs_cves":[{"cvss":7.3,"id":"CVE-2026-5176"}],"_cs_exploited":false,"_cs_products":[],"_cs_severities":["critical"],"_cs_tags":["command-injection","cve-2026-5176","totolink","router"],"_cs_type":"advisory","_cs_vendors":[],"content_html":"\u003cp\u003eA command injection vulnerability, identified as CVE-2026-5176, has been discovered in Totolink A3300R routers running firmware version 17.0.0cu.557_b20221024. The vulnerability resides within the \u003ccode\u003esetSyslogCfg\u003c/code\u003e function located in the \u003ccode\u003e/cgi-bin/cstecgi.cgi\u003c/code\u003e file. An unauthenticated, remote attacker can exploit this flaw by manipulating arguments passed to the vulnerable function. This manipulation results in the execution of arbitrary commands on the affected device. Given the public…\u003c/p\u003e\n","date_modified":"2026-03-31T02:15:59Z","date_published":"2026-03-31T02:15:59Z","id":"/briefs/2026-03-totolink-cve-2026-5176/","summary":"A command injection vulnerability (CVE-2026-5176) exists in the setSyslogCfg function of the Totolink A3300R router version 17.0.0cu.557_b20221024, allowing remote attackers to execute arbitrary commands by manipulating arguments in the /cgi-bin/cstecgi.cgi file.","title":"Totolink A3300R Command Injection Vulnerability (CVE-2026-5176)","url":"https://feed.craftedsignal.io/briefs/2026-03-totolink-cve-2026-5176/"},{"_cs_actors":[],"_cs_cves":[],"_cs_exploited":false,"_cs_products":[],"_cs_severities":["critical"],"_cs_tags":["cve-2026-4976","buffer-overflow","totolink","router","remote-code-execution"],"_cs_type":"advisory","_cs_vendors":[],"content_html":"\u003cp\u003eA critical buffer overflow vulnerability, CVE-2026-4976, has been identified in Totolink LR350 routers running firmware version 9.3.5u.6369_B20220309. The vulnerability resides in the \u003ccode\u003esetWiFiGuestCfg\u003c/code\u003e function within the \u003ccode\u003e/cgi-bin/cstecgi.cgi\u003c/code\u003e file. By crafting a malicious HTTP request and manipulating the \u003ccode\u003essid\u003c/code\u003e argument, a remote, unauthenticated attacker can trigger a buffer overflow, potentially leading to arbitrary code execution on the device. The availability of a public exploit…\u003c/p\u003e\n","date_modified":"2026-03-27T21:17:28Z","date_published":"2026-03-27T21:17:28Z","id":"/briefs/2026-03-totolink-buffer-overflow/","summary":"A buffer overflow vulnerability in Totolink LR350 version 9.3.5u.6369_B20220309 allows a remote attacker to execute arbitrary code by manipulating the 'ssid' argument in the setWiFiGuestCfg function.","title":"Totolink LR350 Remote Buffer Overflow Vulnerability (CVE-2026-4976)","url":"https://feed.craftedsignal.io/briefs/2026-03-totolink-buffer-overflow/"},{"_cs_actors":[],"_cs_cves":[],"_cs_exploited":false,"_cs_products":[],"_cs_severities":["critical"],"_cs_tags":["totolink","rce","command-injection","cve-2026-4611"],"_cs_type":"advisory","_cs_vendors":[],"content_html":"\u003cp\u003eA critical vulnerability, CVE-2026-4611, affects TOTOLINK X6000R routers running firmware versions 9.4.0cu.1360_B20241207 and 9.4.0cu.1498_B20250826. This vulnerability allows a remote attacker to inject operating system commands by manipulating the Hostname argument passed to the \u003ccode\u003esetLanCfg\u003c/code\u003e function within the \u003ccode\u003e/usr/sbin/shttpd\u003c/code\u003e binary. Successful exploitation grants the attacker the ability to execute arbitrary commands with elevated privileges on the router. Given the widespread deployment of these routers in home and small office networks, this vulnerability poses a significant risk of compromise, potentially leading to data theft, botnet recruitment, or denial-of-service attacks. The vulnerability was reported on March 23, 2026.\u003c/p\u003e\n\u003ch2 id=\"attack-chain\"\u003eAttack Chain\u003c/h2\u003e\n\u003col\u003e\n\u003cli\u003eAttacker identifies a vulnerable TOTOLINK X6000R router running firmware version 9.4.0cu.1360_B20241207 or 9.4.0cu.1498_B20250826.\u003c/li\u003e\n\u003cli\u003eThe attacker crafts a malicious HTTP request targeting the \u003ccode\u003e/usr/sbin/shttpd\u003c/code\u003e web server.\u003c/li\u003e\n\u003cli\u003eThe malicious request includes a modified \u003ccode\u003eHostname\u003c/code\u003e argument within the \u003ccode\u003esetLanCfg\u003c/code\u003e function call.\u003c/li\u003e\n\u003cli\u003eThe \u003ccode\u003eHostname\u003c/code\u003e argument contains OS command injection payloads such as backticks, semicolons, or command chaining operators (e.g., \u003ccode\u003e\u0026amp;\u0026amp;\u003c/code\u003e, \u003ccode\u003e||\u003c/code\u003e).\u003c/li\u003e\n\u003cli\u003eThe \u003ccode\u003eshttpd\u003c/code\u003e process, running with elevated privileges, processes the malicious \u003ccode\u003eHostname\u003c/code\u003e argument without proper sanitization.\u003c/li\u003e\n\u003cli\u003eThe injected OS commands are executed by the system shell, leading to arbitrary code execution.\u003c/li\u003e\n\u003cli\u003eThe attacker gains control of the router\u0026rsquo;s operating system.\u003c/li\u003e\n\u003cli\u003eThe attacker can then perform a variety of malicious actions, such as exfiltrating sensitive data, modifying router configurations, or using the router as a foothold for further network attacks.\u003c/li\u003e\n\u003c/ol\u003e\n\u003ch2 id=\"impact\"\u003eImpact\u003c/h2\u003e\n\u003cp\u003eSuccessful exploitation of CVE-2026-4611 allows attackers to execute arbitrary commands on vulnerable TOTOLINK X6000R routers. This could lead to a complete compromise of the device, allowing attackers to steal sensitive information such as Wi-Fi passwords, intercept network traffic, or use the router as a launching point for attacks against other devices on the network. Given the potential for widespread exploitation, a large number of home and small business networks could be affected, resulting in significant financial and reputational damage.\u003c/p\u003e\n\u003ch2 id=\"recommendation\"\u003eRecommendation\u003c/h2\u003e\n\u003cul\u003e\n\u003cli\u003eMonitor web server logs (category: \u003ccode\u003ewebserver\u003c/code\u003e, product: \u003ccode\u003elinux\u003c/code\u003e) for requests containing suspicious characters or command injection attempts within the \u003ccode\u003eHostname\u003c/code\u003e argument when accessing the \u003ccode\u003e/usr/sbin/shttpd\u003c/code\u003e endpoint.\u003c/li\u003e\n\u003cli\u003eImplement the provided Sigma rule to detect exploitation attempts in web server logs.\u003c/li\u003e\n\u003cli\u003eContact TOTOLINK for a security patch or upgrade guidance.\u003c/li\u003e\n\u003cli\u003eConsider implementing network segmentation to limit the impact of a compromised router.\u003c/li\u003e\n\u003c/ul\u003e\n","date_modified":"2026-03-24T12:00:00Z","date_published":"2026-03-24T12:00:00Z","id":"/briefs/2026-03-totolink-rce/","summary":"A remote command injection vulnerability exists in TOTOLINK X6000R routers, specifically versions 9.4.0cu.1360_B20241207 and 9.4.0cu.1498_B20250826, allowing attackers to execute arbitrary commands via manipulation of the Hostname argument in the setLanCfg function.","title":"TOTOLINK X6000R Remote Command Injection Vulnerability","url":"https://feed.craftedsignal.io/briefs/2026-03-totolink-rce/"},{"_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"}