EUVD-2025-18451
CVSS Vector
CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:H
Lifecycle Timeline
4Description
A vulnerability has been found in TP-Link TL-WR940N V4 and TL-WR841N V11. Affected by this issue is some unknown functionality of the file /userRpm/WanSlaacCfgRpm.htm, which may lead to buffer overflow. The attack may be launched remotely. This vulnerability only affects products that are no longer supported by the maintainer.
Analysis
Buffer overflow vulnerability in TP-Link TL-WR940N V4 and TL-WR841N V11 routers, exploitable remotely through the /userRpm/WanSlaacCfgRpm.htm endpoint. An attacker with high privileges can trigger memory corruption leading to availability impact (denial of service) or potential system compromise. This vulnerability affects end-of-life products no longer receiving vendor support, significantly limiting remediation options.
Technical Context
The vulnerability exists in CWE-119 (Improper Restriction of Operations within the Bounds of a Memory Buffer), a classic buffer overflow class affecting memory safety. The vulnerable endpoint /userRpm/WanSlaacCfgRpm.htm handles SLAAC (Stateless Address AutoConfiguration) configuration in IPv6, likely processing user-supplied input without proper bounds checking. TP-Link router firmware typically uses embedded Linux with custom CGI handlers; this specific file is part of the web-based management interface. The affected products are: TP-Link TL-WR940N V4 (CPE: cpe:2.3:h:tp-link:tl-wr940n:4:*:*:*:*:*:*:*) and TP-Link TL-WR841N V11 (CPE: cpe:2.3:h:tp-link:tl-wr841n:11:*:*:*:*:*:*:*). Both are residential-grade wireless routers that reached end-of-life several years ago.
Affected Products
- product: TP-Link TL-WR940N; version: V4; cpe: cpe:2.3:h:tp-link:tl-wr940n:4:*:*:*:*:*:*:*; end_of_life: True - product: TP-Link TL-WR841N; version: V11; cpe: cpe:2.3:h:tp-link:tl-wr841n:11:*:*:*:*:*:*:*; end_of_life: True
Remediation
primary: Hardware replacement; description: No patches will be released for these end-of-life products. Organizations should plan migration to current TP-Link models or alternative vendors with active security support. mitigation: Network segmentation; description: Restrict access to router management interface to trusted administrative networks only. Disable remote management (disable HTTP/HTTPS WAN access to admin interface) if supported. mitigation: Access control; description: Change default administrative credentials immediately. Ensure strong, unique passwords for all administrative accounts to reduce unauthorized access risk. mitigation: Monitoring; description: Monitor router logs for unusual administrative login attempts or configuration changes to /userRpm/WanSlaacCfgRpm.htm endpoint.
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External POC / Exploit Code
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