{"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":"<strong>CVE-2025-11091: Remote Buffer Overflow Vulnerability in Tenda AC21 Router<\/strong>"},"content":{"rendered":"<p><strong>Overview<\/strong><\/p>\n<p>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 &#8216;sscanf&#8217; of the file &#8216;\/goform\/SetStaticRouteCfg&#8217;, leading to a buffer overflow. The flaw is of critical concern as it allows <a href=\"https:\/\/www.ameeba.com\/blog\/cve-2025-47579-critical-deserialization-of-untrusted-data-vulnerability-in-themegoods-photography\/\"  data-wpil-monitor-id=\"88978\">remote<\/a> attackers to potentially compromise systems and leak sensitive data. Given the widespread use of Tenda AC21 routers, this <a href=\"https:\/\/www.ameeba.com\/blog\/cve-2025-9693-arbitrary-file-deletion-vulnerability-in-user-meta-user-profile-builder-plugin-for-wordpress\/\"  data-wpil-monitor-id=\"90598\">vulnerability poses a substantial threat to both individual users<\/a> and organizations alike.<\/p>\n<p><strong>Vulnerability Summary<\/strong><\/p>\n<p>CVE ID: CVE-2025-11091<br \/>\nSeverity: High (8.8 CVSS v3)<br \/>\nAttack Vector: Network<br \/>\nPrivileges Required: None<br \/>\nUser Interaction: None<br \/>\nImpact: <a href=\"https:\/\/www.ameeba.com\/blog\/cve-2025-9443-buffer-overflow-vulnerability-in-tenda-ch22-1-0-0-1-potentially-leads-to-system-compromise\/\"  data-wpil-monitor-id=\"89010\">System compromise and potential<\/a> data leakage<\/p>\n<p><strong>Affected Products<\/strong><\/p><div id=\"ameeb-498396618\" class=\"ameeb-content-2 ameeb-entity-placement\"><div style=\"border-left: 4px solid #555; padding-left: 20px; margin: 48px 0; font-family: Roboto, sans-serif; color: #ffffff; line-height: 1.6; max-width: 700px;\">\r\n  <h2 style=\"margin-top: 0; font-size: 20px; font-weight: 600; display: flex; align-items: center;\">\r\n    <a href=\"https:\/\/www.ameeba.com\/chat\" style=\"display: inline-flex; align-items: center; margin-right: 8px;\">\r\n      <img decoding=\"async\" src=\"https:\/\/www.ameeba.com\/blog\/wp-content\/uploads\/2025\/10\/Best-App-icon-Ameeba.png\" alt=\"Ameeba Chat Icon\" style=\"width: 40px; height: 40px;\" \/>\r\n    <\/a>\r\n    A new way to communicate\r\n  <\/h2>\r\n\r\n  <p style=\"margin-bottom: 12px;\">\r\n    Ameeba Chat is built on encrypted identity, not personal profiles.\r\n  <\/p>\r\n\r\n  <p style=\"margin-bottom: 16px;\">\r\n    Message, call, share files, and coordinate with identities kept separate.\r\n  <\/p>\r\n\r\n  <ul style=\"list-style: none; padding-left: 0; margin-bottom: 20px;\">\r\n    <li>\u2022 Encrypted identity<\/li>\r\n    <li>\u2022 Ameeba Chat authenticates access<\/li>\r\n    <li>\u2022 Aliases and categories<\/li>\r\n    <li>\u2022 End-to-end encrypted chat, calls, and files<\/li>\r\n    <li>\u2022 Secure notes for sensitive information<\/li>\r\n  <\/ul>\r\n\r\n  <p style=\"font-style: italic; font-weight: 600; margin-bottom: 24px;\">\r\n    Private communication, rethought.\r\n  <\/p>\r\n\r\n  <div style=\"display: flex; flex-wrap: wrap; gap: 12px;\">\r\n    <a href=\"https:\/\/www.ameeba.com\/chat\/download\" style=\"background-color: #ffffff; color: #000000; padding: 10px 20px; text-decoration: none; border-radius: 6px; font-weight: 500;\">Download Ameeba Chat<\/a>\r\n    <a href=\"https:\/\/www.ameeba.com\/chat\" style=\"border: 1px solid #ffffff; color: #ffffff; padding: 10px 20px; text-decoration: none; border-radius: 6px; font-weight: 500;\">Learn More<\/a>\r\n  <\/div>\r\n<\/div>\r\n<\/div>\n<p>Product | Affected Versions<\/p>\n<p>Tenda AC21 | Up to 16.03.08.16<\/p>\n<p><strong>How the Exploit Works<\/strong><\/p>\n<p>The <a href=\"https:\/\/www.ameeba.com\/blog\/cve-2025-54236-critical-improper-input-validation-vulnerability-in-adobe-commerce-leading-to-session-takeover\/\"  data-wpil-monitor-id=\"88829\">vulnerability lies in the improper<\/a> handling of arguments by the &#8216;sscanf&#8217; function in the &#8216;\/goform\/SetStaticRouteCfg&#8217; file. By manipulating the argument list, an attacker can trigger a <a href=\"https:\/\/www.ameeba.com\/blog\/cve-2025-9527-remote-stack-based-buffer-overflow-vulnerability-in-linksys-e1700-routers\/\"  data-wpil-monitor-id=\"88564\">buffer overflow<\/a> condition. This overflow allows the attacker to <a href=\"https:\/\/www.ameeba.com\/blog\/cve-2024-37777-remote-code-execution-vulnerability-in-o2oa-v9-0-3\/\"  data-wpil-monitor-id=\"88576\">execute arbitrary code<\/a>, possibly leading to a complete system compromise or the leakage of sensitive data.<\/p>\n<p><strong>Conceptual Example Code<\/strong><\/p><div id=\"ameeb-3658624294\" class=\"ameeb-content ameeb-entity-placement\"><div class=\"poptin-embedded\" data-id=\"f6b387694f681\"><\/div>\r\n\r\n\r\n\r\n\r\n\r\n<\/div>\n<p>An attacker might exploit this <a href=\"https:\/\/www.ameeba.com\/blog\/cve-2025-7812-critical-cross-site-request-forgery-vulnerability-in-video-share-vod-wordpress-plugin\/\"  data-wpil-monitor-id=\"88558\">vulnerability by sending a specially crafted HTTP request<\/a>, as illustrated in this conceptual example:<\/p>\n<pre><code class=\"\" data-line=\"\">POST \/goform\/SetStaticRouteCfg HTTP\/1.1\nHost: target_router_ip\nContent-Type: application\/x-www-form-urlencoded\nrouteName=Default+Route&amp;routeDest=0.0.0.0&amp;routeMask=0.0.0.0&amp;routeGateway=x.x.x.x&amp;routeMetric=1&amp;routeInf=br0%00{payload}<\/code><\/pre>\n<p>In this example, `{payload}` represents a maliciously crafted sequence of bytes designed to <a href=\"https:\/\/www.ameeba.com\/blog\/cve-2025-10120-critical-buffer-overflow-vulnerability-in-tenda-ac20-routers\/\"  data-wpil-monitor-id=\"88589\">overflow the buffer<\/a> and execute arbitrary code.<\/p>\n<p><strong>Recommended Mitigations<\/strong><\/p>\n<p>To <a href=\"https:\/\/www.ameeba.com\/blog\/cve-2025-43728-protection-mechanism-failure-vulnerability-in-dell-thinos\/\"  data-wpil-monitor-id=\"90241\">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 <a href=\"https:\/\/www.ameeba.com\/blog\/cve-2025-59033-critical-vulnerability-in-microsoft-s-driver-block-list\/\"  data-wpil-monitor-id=\"88607\">block attempts to exploit this vulnerability<\/a>.<\/p>\n","protected":false},"excerpt":{"rendered":"<p>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 &#8216;sscanf&#8217; of the file &#8216;\/goform\/SetStaticRouteCfg&#8217;, leading to a buffer overflow. The flaw is of critical concern as it allows remote attackers to potentially compromise systems and leak sensitive data. [&hellip;]<\/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,"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":[],"_links":{"self":[{"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/posts\/81139","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/comments?post=81139"}],"version-history":[{"count":10,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/posts\/81139\/revisions"}],"predecessor-version":[{"id":83542,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/posts\/81139\/revisions\/83542"}],"wp:attachment":[{"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/media?parent=81139"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/categories?post=81139"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/tags?post=81139"},{"taxonomy":"vendor","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/vendor?post=81139"},{"taxonomy":"product","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/product?post=81139"},{"taxonomy":"attack_vector","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/attack_vector?post=81139"},{"taxonomy":"asset_type","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/asset_type?post=81139"},{"taxonomy":"severity","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/severity?post=81139"},{"taxonomy":"exploit_status","embeddable":true,"href":"https:\/\/www.ameeba.com\/blog\/wp-json\/wp\/v2\/exploit_status?post=81139"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}