{"description":"Trending threats, MITRE ATT\u0026CK coverage, and detection metadata. Fed continuously.","feed_url":"https://feed.craftedsignal.io/products/w6-s/feed.json","home_page_url":"https://feed.craftedsignal.io/","items":[{"_cs_actors":[],"_cs_cpes":[],"_cs_cves":[{"cvss":9.8,"id":"CVE-2026-67822"}],"_cs_exploited":false,"_cs_has_poc":false,"_cs_poc_references":[],"_cs_products":["W6-S"],"_cs_severities":["critical"],"_cs_tags":["vulnerability","iot","rce","dos"],"_cs_type":"advisory","_cs_vendors":["Tenda"],"content_html":"\u003cp\u003eCVE-2026-67822 is a critical stack-based buffer overflow vulnerability affecting Tenda W6-S wireless access points running firmware version v1.0.0.4(510). The vulnerability resides in the form handler \u003ccode\u003eformwrlSSIDset()\u003c/code\u003e within the device's GoAhead-derived \u003ccode\u003e/bin/httpd\u003c/code\u003e web server. An attacker can trigger the overflow by sending a crafted HTTP POST request to the \u003ccode\u003e/goform/wifiSSIDset\u003c/code\u003e endpoint. Specifically, the \u003ccode\u003eGO\u003c/code\u003e and \u003ccode\u003eindex\u003c/code\u003e parameters are copied into a fixed 64-byte stack buffer using an unchecked \u003ccode\u003esprintf\u003c/code\u003e operation, allowing for memory corruption.\u003c/p\u003e\n\u003cp\u003eProof-of-concept exploits are publicly available, demonstrating confirmed denial of service (system crash) and providing a skeleton for potential remote code execution. Because the affected firmware lacks modern exploit mitigations like stack canaries and ASLR on the MIPS architecture, this flaw poses a high risk to unpatched devices.\u003c/p\u003e\n\u003ch2 id=\"attack-chain\"\u003eAttack Chain\u003c/h2\u003e\n\u003col\u003e\n\u003cli\u003eThe attacker performs reconnaissance to identify Tenda W6-S devices reachable over the network.\u003c/li\u003e\n\u003cli\u003eThe attacker crafts an HTTP POST request targeting the \u003ccode\u003e/goform/wifiSSIDset\u003c/code\u003e endpoint.\u003c/li\u003e\n\u003cli\u003eThe \u003ccode\u003eGO\u003c/code\u003e parameter is populated with a payload significantly exceeding 64 bytes to overflow the target buffer.\u003c/li\u003e\n\u003cli\u003eThe web server process (\u003ccode\u003e/bin/httpd\u003c/code\u003e) receives the malicious input through the standard HTTP request body.\u003c/li\u003e\n\u003cli\u003eThe \u003ccode\u003esprintf\u003c/code\u003e function writes the oversized payload into the fixed 64-byte stack buffer, overwriting adjacent memory, including the saved return address (\u003ccode\u003e$ra\u003c/code\u003e).\u003c/li\u003e\n\u003cli\u003eThe function returns control to the address specified by the attacker (the corrupted \u003ccode\u003e$ra\u003c/code\u003e).\u003c/li\u003e\n\u003cli\u003eIf used for DoS, the process crashes and the web management interface stops responding until the device is power-cycled.\u003c/li\u003e\n\u003cli\u003eIf used for RCE, the attacker directs execution flow to shellcode or a ROP chain to achieve arbitrary code execution.\u003c/li\u003e\n\u003c/ol\u003e\n\u003ch2 id=\"impact\"\u003eImpact\u003c/h2\u003e\n\u003cp\u003eThe vulnerability is rated CVSS 9.8, indicating full impact on confidentiality, integrity, and availability. Successful exploitation typically results in a denial of service, rendering the W6-S wireless access point management interface unreachable. In targeted scenarios, the lack of stack protection on the device firmware allows for potential remote code execution, granting an attacker full control over the wireless access point and a foothold in the local network segment.\u003c/p\u003e\n\u003ch2 id=\"recommendation\"\u003eRecommendation\u003c/h2\u003e\n\u003cp\u003ePrioritize patching or isolating affected Tenda W6-S devices until a vendor-supplied update is verified.\u003c/p\u003e\n\u003cul\u003e\n\u003cli\u003eBlock inbound traffic to the management interface of Tenda W6-S devices on the network perimeter.\u003c/li\u003e\n\u003cli\u003eDeploy the Sigma rule below to monitor for large, malformed POST requests to the \u003ccode\u003e/goform/wifiSSIDset\u003c/code\u003e endpoint, which are indicative of exploitation attempts.\u003c/li\u003e\n\u003cli\u003eIf firmware updates are unavailable, disable remote management capabilities and restrict access to the management web server to a dedicated, isolated VLAN.\u003c/li\u003e\n\u003c/ul\u003e\n","date_modified":"2026-08-07T15:53:14Z","date_published":"2026-08-07T15:53:14Z","id":"https://feed.craftedsignal.io/briefs/2026-08-tenda-w6-s-overflow/","summary":"A critical stack-based buffer overflow in the Tenda W6-S web management interface allows unauthenticated remote attackers to cause a denial of service or potentially execute arbitrary code.","title":"Critical Stack Overflow in Tenda W6-S wifiSSIDset Endpoint","url":"https://feed.craftedsignal.io/briefs/2026-08-tenda-w6-s-overflow/"}],"language":"en","title":"CraftedSignal Threat Feed - W6-S","version":"https://jsonfeed.org/version/1.1"}