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Vulnerability Intelligence

CVE-2025-34037

CriticalExploitedPublic exploit

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.

Published Jun 23, 2025 · Updated Jul 22, 2026

Key Facts

Patch immediately
  • CVE-2025-34037 is a critical-severity vulnerability (CVSS 10.0 v4) affecting E1000 v1, E1200 v1, E1500 v1 and 8 more products.
  • It is exploited in the wild, listed in Industry KEV feed, CIRCL KEV since Jun 23, 2025. Public exploit code is available.
  • EPSS estimates a 93% probability of exploitation in the next 30 days.
  • Fixed versions are available, including E1000 v1 2.1.03, E1500 v1 1.0.06, E2500 v1/v2 2.0.00.
  • Brandefense priority: patch immediately, because it is listed as exploited in the wild.

CVSS v4

10.0

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

EPSS (30-day exploit likelihood)

93%

Higher than 99.8% of all scored CVEs

Exploited in the wild

Yes

2 catalog listings

Public exploit code

Available

Proof-of-concept or weaponized module

Get the full CVE-2025-34037 brief as a PDF

Every affected product and fixed release, exploitation status and a first 24 hours response checklist, emailed within minutes.

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.

Known-Exploited Catalog Listings

CatalogAddedRemediation dueRansomware use
Industry KEV feedJun 23, 2025n/aNot reported
CIRCL KEVJan 9, 2026n/aNot reported

Required action: Apply remediations or mitigations per vendor instructions or discontinue use of the product if remediation or mitigations are unavailable.

Affected Products

11 affected entries in total
ProductAffected versionsFixed in
E1000 v1See advisory2.1.03
E1200 v1See advisoryn/a
E1500 v1See advisory1.0.06
E1550See advisoryn/a
E2000See advisoryn/a
6 more affected products in the full CVE brief

Patched Releases

E1000 v1

2.1.03

E1500 v1

1.0.06

E2500 v1/v2

2.0.00

E3000

1.0.06

E3200

1.0.05

E4200

1.0.06

E900 v1

1.0.04

Timeline

  1. Publicly disclosed

    Jun 23, 2025

  2. Added to Industry KEV feed

    Jun 23, 2025

  3. Added to CIRCL KEV

    Jan 9, 2026

  4. Last updated

    Jul 22, 2026

Weakness Type

  • CWE-78 Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')

References

9 more references in the full CVE brief

FAQ

Common Questions.

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