{"id":59783,"date":"2025-07-31T19:19:55","date_gmt":"2025-07-31T19:19:55","guid":{"rendered":""},"modified":"2025-09-27T02:05:13","modified_gmt":"2025-09-27T08:05:13","slug":"cve-2025-8140-critical-buffer-overflow-vulnerability-in-totolink-a702r","status":"publish","type":"post","link":"https:\/\/www.ameeba.com\/blog\/cve-2025-8140-critical-buffer-overflow-vulnerability-in-totolink-a702r\/","title":{"rendered":"CVE-2025-8140: Critical Buffer Overflow Vulnerability in TOTOLINK A702R<\/strong>"},"content":{"rendered":"

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

A severe and critical vulnerability has been discovered in the TOTOLINK A702R 4.0.0-B20230721.1521, a widely used wireless network router. The flaw is not only dangerous due to its high severity score but also because it exposes an unknown part of the code to potential attackers, potentially leading to system compromise or data leakage. As TOTOLINK’s products are widely used in various industries, the scope of this vulnerability is broad, and it’s crucial to understand its implications and apply appropriate mitigation strategies.<\/p>\n

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

CVE ID: CVE-2025-8140
\nSeverity: Critical, CVSS score 8.8
\nAttack Vector: Remote, HTTP POST Request
\nPrivileges Required: None
\nUser Interaction: None
\nImpact: Potential system<\/a> compromise or data leakage<\/p>\n

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

Product | Affected Versions<\/p>\n

TOTOLINK A702R<\/a> | 4.0.0-B20230721.1521<\/p>\n

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

The vulnerability arises from an insecure handling of HTTP POST requests in the ‘submit-url’ argument of the file ‘\/boafrm\/formWlanMultipleAP.’ The improper validation and processing of this argument can lead to a buffer<\/a> overflow condition. Buffer overflow is a classic vulnerability<\/a> in which an application writes more data to a block of allocated memory (buffer) than it can hold, causing an overflow. This overflow can overwrite adjacent memory areas, potentially leading to arbitrary code execution<\/a>, system crashes, and information disclosure.<\/p>\n

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

Below is a conceptual example of how the vulnerability might be exploited using a malformed HTTP POST request:<\/a><\/p>\n

POST \/boafrm\/formWlanMultipleAP HTTP\/1.1\nHost: target.example.com\nContent-Type: application\/x-www-form-urlencoded\nsubmit-url=<\/code><\/pre>\n
In the above pseudocode, `` would be replaced with an oversized, specifically crafted string designed to overflow the buffer<\/a> and potentially alter the program’s execution flow.<\/p>\n
Mitigation Guidance<\/strong><\/p>\n
The best way to mitigate this vulnerability is to apply the vendor-issued patch as soon as it becomes available. This patch will likely involve correcting the input validation for the ‘submit-url’ argument, preventing the possibility of buffer overflow<\/a>.
\nIn the meantime, users can implement a Web Application<\/a> Firewall (WAF) or Intrusion Detection System (IDS) as temporary mitigation. These systems can be configured to detect and block attempts to exploit this vulnerability<\/a>. However, this should be considered a temporary solution and not a replacement for the vendor’s patch.<\/p>\n","protected":false},"excerpt":{"rendered":"
Overview A severe and critical vulnerability has been discovered in the TOTOLINK A702R 4.0.0-B20230721.1521, a widely used wireless network router. The flaw is not only dangerous due to its high severity score but also because it exposes an unknown part of the code to potential attackers, potentially leading to system compromise or data leakage. As […]<\/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":[86,80],"asset_type":[],"severity":[],"exploit_status":[],"class_list":["post-59783","post","type-post","status-publish","format-standard","hentry","category-uncategorized","attack_vector-buffer-overflow","attack_vector-rce"],"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