How severe is CVE-2025-34037?

CVE-2025-34037 has a CVSS 4.0 base score of 10.0, rated critical severity.

Is CVE-2025-34037 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 85% (100th percentile), an estimate of the probability of exploitation in the next 30 days.

How do I fix CVE-2025-34037?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.

Does CVE-2025-34037 have an EU (EUVD) identifier?

Yes. CVE-2025-34037 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-18964.

When was CVE-2025-34037 published?

CVE-2025-34037 was published on 2025-06-24 and last updated on 2026-06-17.

CVE-2025-34037

CVE-2025-34037 is a critical-severity vulnerability with a CVSS 4.0 base score of 10.0. Its EPSS exploit-prediction score of 85% places it in the 100th percentile, indicating an elevated likelihood of exploitation. The underlying weakness is classified as CWE-78.

Key facts

Severity: Critical (CVSS 4.0 base score 10.0)
EPSS exploit prediction: 85% (100th percentile)
Actively exploited: Not listed in CISA KEV
EU (EUVD) id: EUVD-2025-18964
Weakness: CWE-78
Published: 2025-06-24
Last modified: 2026-06-17

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.

Frequently asked questions

What is 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. 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.
How severe is CVE-2025-34037?: CVE-2025-34037 has a CVSS 4.0 base score of 10.0, rated critical severity.
Is CVE-2025-34037 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 85% (100th percentile), an estimate of the probability of exploitation in the next 30 days.
How do I fix CVE-2025-34037?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its critical severity, prioritise patching exposed systems.
Does CVE-2025-34037 have an EU (EUVD) identifier?: Yes. CVE-2025-34037 is tracked in the ENISA EU Vulnerability Database (EUVD) as EUVD-2025-18964.
When was CVE-2025-34037 published?: CVE-2025-34037 was published on 2025-06-24 and last updated on 2026-06-17.

References

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