{"description":"Trending threats, MITRE ATT\u0026CK coverage, and detection metadata — refreshed continuously.","feed_url":"https://feed.craftedsignal.io/tags/cve-2026-5677/","home_page_url":"https://feed.craftedsignal.io/","items":[{"_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/"}],"language":"en","title":"CraftedSignal Threat Feed — Cve-2026-5677","version":"https://jsonfeed.org/version/1.1"}