SOC status:Duty analyst on shift

UK Cyber Defence
VulnerabilityDeferred

CVE-2025-34037

An OS command injection vulnerability exists in various models of E-Series Linksys routers via the /tmUnblock.cgi and /hndUnblock.cgi endpoints over HTTP on port 8080.

CRITICAL 10.0EPSS 96.2%

Does this matter?

EPSS puts the probability of exploitation in the next 30 days at 96.2%, higher than 100% of all known CVEs. Patch or mitigate before the next change window.

Description

An OS command injection vulnerability exists in various models of E-Series Linksys routers via the /tmUnblock.cgi and /hndUnblock.cgi endpoints over HTTP on port 8080. The CGI scripts improperly process user-supplied input passed to the ttcp_ip parameter without sanitization, allowing unauthenticated attackers to inject shell commands. This vulnerability was reported to be exploited in the wild by the "TheMoon" worm  in 2014 to deploy a MIPS ELF payload, enabling arbitrary code execution on the router. Additionally, this vulnerability may affect other Linksys products to include, but not limited to, WAG/WAP/WES/WET/WRT-series router models and Wireless-N access points and routers. Exploitation evidence was observed by the Shadowserver Foundation on 2025-02-06 UTC.

CVSS 4.0
10.0 CRITICALCVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:H/SI:H/SA:H/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/M
EPSS
96.15% probability · 100th percentile
Public exploits
None in Exploit-DB
CISA KEV
Not listed
Weakness
CWE-78
Source
disclosure@vulncheck.com
EPSS trend
0%50%100%25 September 2026: 92.77%25 October 2026: 96.15%26 October 2026: 96.15%25 September 202626 October 2026

EPSS moved from 92.8% on 25 September 2026 to 96.2% on 26 October 2026. The dashed line is the ten per cent mark our analysts treat as “patch before the next change window”.

Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.