Priority reviewCritical

CVE-2025-34037

Linksys E4200, E3200, E3000

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 lim...

CVSS: 10
EPSS: 86.2%
CISA KEV: Not listed
Published: 2025.06.24

PRIORITY ASSESSMENT

Priority review

FIRST EPSS indicates an elevated probability of exploitation.

Known exploitationNot established by KEV

Exploit probability86.2%

Technical severityCVSS 10

Vulnerability overview

Affected product and versions

Product: Linksys E4200, E3200, E3000
Affected versions: < 1.0.06, < 1.0.05, < 2.0.00, <= 1.0.05, <= 1.0.03, <= 1.0.04, < 2.1.03, < 1.0.04
Fixed versions: No verified fixed-version field is available yet

Recommended response sequence

Confirm exposure before applying a vendor-supported change.

Full remediation guide

1
Identify
Confirm that Linksys E4200, E3200, E3000 and an affected version are present.
2
Prioritize
Combine exploitation signals with asset exposure and business criticality.
3
Remediate
Follow the vendor advisory or supported update path and preserve rollback options.
4
Verify
Recheck the version, service health, access paths, and relevant logs.

Technical data

CVSS vector: CVSS: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/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X
CWE: CWE-78