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Linksys WRT120N tmUnblock.cgi Stack-Based Buffer Overflow Admin Password Reset

Priority MEDIUM 57CWE-121Published · Updated

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

Exploitation Proof of concept CISA SSVC · not in CISA KEV
EPSS 0.01274 70th percentileScored 2026-11-07
Public exploit Yes 3 exploit referencesTagged by the CNA
Fix No fix listed No fixed version in the sources yet

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

VendorProductAffected versionsFixed inStatusSource
LinksysWRT120N1.0.07—No fix listedCNA
  • WRT120N VendorLinksys Affected 1.0.07 Fixed in — No fix listed CNA

Remediation

No fixed version listed by the sources yet.

Timeline

  1. 2026-10-02 Threatist record created from CVE-2014-125122
  2. 2026-10-03 Alias added: GHSA-6r87-23pq-fxxg

References

  • 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
See all 253 →

Sources