Linksys WRT120N tmUnblock.cgi Stack-Based Buffer Overflow Admin Password Reset
Key facts
- Attack vector
- Adjacent network
- Privileges required
- None
- User interaction
- None
- Attack complexity
- Low
- Attack requirements
- None
- Impact type
- —
- Confidentiality · integrity · availability
- Low · Low · Low
- Fix status
- No fix listed
Attack profile from CVSS 4.0 · CNA. Fix status from CNA.
Summary
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.
Why it matters now
SSVC decision points
CISA ADP · SSVC 2.0.3
- Exploitation
- Poc
- Automatable
- No
- Technical impact
- Partial
The decision (Track, Attend, Act) also depends on your mission and well-being impact; see CISA's SSVC guide.
Affected products
Remediation
No fixed version listed by the sources yet.
Timeline
- 2026-10-02 Threatist record created from CVE-2014-125122
- 2026-10-03 Alias added: GHSA-6r87-23pq-fxxg
References
More Linksys vulnerabilities
- TI-2025-24206 Linksys Routers E/WAG/WAP/WES/WET/WRT-Series CVSS 4.0CRITICAL 10.0
- TI-2017-12715 OS command injection in Linksys WVBR0 CVSS 3.0CRITICAL 9.8
- TI-2026-70977 Stack-based buffer overflow in Linksys E1700 Mac Filter CVSS 4.0CRITICAL 10.0
- TI-2026-22199 Missing neutralization in Linksys MR9600, Linksys MX4200 CVSS 3.1CRITICAL 9.8
- TI-2026-22198 Missing neutralization in Linksys MR9600, Linksys MX4200 CVSS 3.1CRITICAL 9.8
- TI-2026-22197 Missing authentication in Linksys MR9600, Linksys MX4200 CVSS 3.1CRITICAL 9.8
Sources
- CVE-2014-125122 · CVE Program
- CVE-2014-125122 · NVD
- FIRST EPSS
- GHSA-6r87-23pq-fxxg · GitHub Advisory Database · CC BY 4.0
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