Description
A stack-based buffer overflow vulnerability exists in the tmUnblock.cgi endpoint of the Linksys WRT120N wireless router. The vulnerability is triggered by sending a specially crafted HTTP POST request with an overly long TM_Block_URL parameter to the endpoint. By exploiting this flaw, an unauthenticated remote attacker can overwrite memory in a controlled manner, enabling them to temporarily reset the administrator password of the device to a blank value. This grants unauthorized access to the router’s web management interface without requiring valid credentials.
Affected products
| Vendor | Product | Affected | Fixed |
|---|---|---|---|
| Linksys | WRT120N | 1.0.07 | — |
Public exploits
Exploit or proof-of-concept code for this vulnerability is publicly available, which lowers the bar for attackers. Treat it as a reason to patch sooner.
Metasploit 1 module
-
Linksys WRT120N tmUnblock Stack Buffer Overflow
auxiliary/admin/http/linksys_tmunblock_admin_reset_bof
Sources: PoC-in-GitHub, Metasploit Framework, Exploit-DB — updated daily. Only links are listed; no exploit code is hosted here.
References
- https://raw.githubusercontent.com/rapid7/metasploit-framework/master/modules/auxiliary/admin/http/linksys_tmunblock_admin_reset_bof.rb exploit
- https://www.exploit-db.com/exploits/31758 exploit
- https://web.archive.org/web/20210424073058/http://www.devttys0.com/2014/02/wrt120n-fprintf-stack-overflow/ technical-description exploit
- https://www.vulncheck.com/advisories/linksys-wrt120n-stack-based-buffer-overflow-admin-password-reset third-party-advisory