{"id":81139,"date":"2025-10-03T11:46:29","date_gmt":"2025-10-03T11:46:29","guid":{"rendered":""},"modified":"2025-10-21T04:13:22","modified_gmt":"2025-10-21T10:13:22","slug":"cve-2025-11091-remote-buffer-overflow-vulnerability-in-tenda-ac21-router","status":"publish","type":"post","link":"https:\/\/www.ameeba.com\/blog\/cve-2025-11091-remote-buffer-overflow-vulnerability-in-tenda-ac21-router\/","title":{"rendered":"CVE-2025-11091: Remote Buffer Overflow Vulnerability in Tenda AC21 Router<\/strong>"},"content":{"rendered":"

Overview<\/strong><\/p>\n

A significant security vulnerability, identified as CVE-2025-11091, has recently been discovered in Tenda AC21 routers up to version 16.03.08.16. This vulnerability specifically affects the function ‘sscanf’ of the file ‘\/goform\/SetStaticRouteCfg’, leading to a buffer overflow. The flaw is of critical concern as it allows remote<\/a> attackers to potentially compromise systems and leak sensitive data. Given the widespread use of Tenda AC21 routers, this vulnerability poses a substantial threat to both individual users<\/a> and organizations alike.<\/p>\n

Vulnerability Summary<\/strong><\/p>\n

CVE ID: CVE-2025-11091
\nSeverity: High (8.8 CVSS v3)
\nAttack Vector: Network
\nPrivileges Required: None
\nUser Interaction: None
\nImpact: System compromise and potential<\/a> data leakage<\/p>\n

Affected Products<\/strong><\/p>\n

Product | Affected Versions<\/p>\n

Tenda AC21 | Up to 16.03.08.16<\/p>\n

How the Exploit Works<\/strong><\/p>\n

The vulnerability lies in the improper<\/a> handling of arguments by the ‘sscanf’ function in the ‘\/goform\/SetStaticRouteCfg’ file. By manipulating the argument list, an attacker can trigger a buffer overflow<\/a> condition. This overflow allows the attacker to execute arbitrary code<\/a>, possibly leading to a complete system compromise or the leakage of sensitive data.<\/p>\n

Conceptual Example Code<\/strong><\/p>\n

An attacker might exploit this vulnerability by sending a specially crafted HTTP request<\/a>, as illustrated in this conceptual example:<\/p>\n

POST \/goform\/SetStaticRouteCfg HTTP\/1.1\nHost: target_router_ip\nContent-Type: application\/x-www-form-urlencoded\nrouteName=Default+Route&routeDest=0.0.0.0&routeMask=0.0.0.0&routeGateway=x.x.x.x&routeMetric=1&routeInf=br0%00{payload}<\/code><\/pre>\n
In this example, `{payload}` represents a maliciously crafted sequence of bytes designed to overflow the buffer<\/a> and execute arbitrary code.<\/p>\n
Recommended Mitigations<\/strong><\/p>\n
To protect against this vulnerability<\/a>, users are advised to apply the patch provided by the vendor as soon as it becomes available. In the interim, users can mitigate the risk by implementing a Web Application Firewall (WAF) or an Intrusion Detection System (IDS) to detect and block attempts to exploit this vulnerability<\/a>.<\/p>\n","protected":false},"excerpt":{"rendered":"
Overview A significant security vulnerability, identified as CVE-2025-11091, has recently been discovered in Tenda AC21 routers up to version 16.03.08.16. This vulnerability specifically affects the function ‘sscanf’ of the file ‘\/goform\/SetStaticRouteCfg’, leading to a buffer overflow. The flaw is of critical concern as it allows remote attackers to potentially compromise systems and leak sensitive data. […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"om_disable_all_campaigns":false,"_monsterinsights_skip_tracking":false,"footnotes":""},"categories":[1],"tags":[],"vendor":[],"product":[],"attack_vector":[86],"asset_type":[],"severity":[],"exploit_status":[],"class_list":["post-81139","post","type-post","status-publish","format-standard","hentry","category-uncategorized","attack_vector-buffer-overflow"],"aioseo_notices":[],"aioseo_head":"\n\t\t\n\t\n\t\n\t\n\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t