{"id":71991,"date":"2025-09-06T17:03:09","date_gmt":"2025-09-06T17:03:09","guid":{"rendered":""},"modified":"2025-10-10T05:20:43","modified_gmt":"2025-10-10T11:20:43","slug":"cve-2025-9781-critical-buffer-overflow-vulnerability-in-totolink-a702r","status":"publish","type":"post","link":"https:\/\/www.ameeba.com\/blog\/cve-2025-9781-critical-buffer-overflow-vulnerability-in-totolink-a702r\/","title":{"rendered":"CVE-2025-9781: Critical Buffer Overflow Vulnerability in TOTOLINK A702R<\/strong>"},"content":{"rendered":"

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

In the ever-evolving world of cybersecurity, new vulnerabilities are a common occurrence. One such critical vulnerability has been discovered in TOTOLINK A702R version 4.0.0-B20211108.1423. This vulnerability, assigned the identifier CVE-2025-9781, is a severe threat to all users of the affected product as the exploit can be initiated remotely, potentially leading to system<\/a> compromise or data leakage.
\nThis vulnerability is particularly concerning due<\/a> to the high CVSS severity score of 8.8, indicating a high impact upon successful exploitation. This blog post aims to detail the vulnerability<\/a>, its impact, and the necessary steps to mitigate the threat.<\/p>\n

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

CVE ID: CVE-2025-9781
\nSeverity: Critical (8.8 CVSS Score)
\nAttack Vector: Network
\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-B20211108.1423<\/p>\n

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

The vulnerability lies in the handling<\/a> of the ‘ip6addr’ argument in the function ‘sub_4162DC’ of the file ‘\/boafrm\/formFilter. By manipulating this argument, an attacker can cause a buffer overflow<\/a> condition. Buffer overflows<\/a> occur when more data is written to a piece of memory than it can handle, which can cause data to spill over into adjacent memory spaces.
\nIn this case, an attacker could send a specially crafted request containing a long ‘ip6addr’ argument to the target device. This overflow can corrupt memory and potentially allow for the execution of arbitrary code<\/a> or cause a denial of service.<\/p>\n

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

Here is a conceptual example of how the vulnerability might be exploited:<\/p>\n

POST \/boafrm\/formFilter HTTP\/1.1\nHost: target.example.com\nContent-Type: application\/x-www-form-urlencoded\nip6addr=0201:0db8:85a3:0000:0000:8a2e:0370:7334...[additional data]<\/code><\/pre>\n
In this example, the ‘ip6addr’ argument is filled with more data than it can handle, leading to a buffer<\/a> overflow.
\nPlease note that this is a simplified and conceptual example. Real-world exploits may involve additional techniques or steps to successfully exploit the vulnerability.<\/p>\n
Mitigation<\/strong><\/p>\n
The vendor has issued a patch for the affected<\/a> product. Users are strongly advised to apply this patch immediately. If unable to patch immediately, users should consider using a Web Application Firewall (WAF) or Intrusion Detection System (IDS) as a temporary mitigation measure, although these are not guaranteed to fully protect against the exploit.<\/p>\n","protected":false},"excerpt":{"rendered":"
Overview In the ever-evolving world of cybersecurity, new vulnerabilities are a common occurrence. One such critical vulnerability has been discovered in TOTOLINK A702R version 4.0.0-B20211108.1423. This vulnerability, assigned the identifier CVE-2025-9781, is a severe threat to all users of the affected product as the exploit can be initiated remotely, potentially leading to system compromise or […]<\/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":[86,87],"asset_type":[],"severity":[],"exploit_status":[],"class_list":["post-71991","post","type-post","status-publish","format-standard","hentry","category-uncategorized","attack_vector-buffer-overflow","attack_vector-dos"],"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