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TI-2021-02500 Aliases CVE-2021-3547GHSA-2cgw-c87g-ww8q

Authentication bypass in OpenVPN 3 Core Library

Priority LOW 35CWE-305Published · Updated

Key facts

Attack vector
Network
Privileges required
None
User interaction
None
Attack complexity
High
Impact type
Spoofing
Confidentiality · integrity · availability
High · High · None
Fix status
No fix listed

Attack profile from CVSS 3.1 · NVD. Fix status from CNA. Impact type from CWE-295.

Summary

OpenVPN 3 Core Library version 3.6 and 3.6.1 allows a man-in-the-middle attacker to bypass the certificate authentication by issuing an unrelated server certificate using the same hostname found in the verify-x509-name option in a client configuration.

Why it matters now

EPSS 0.01238 69th percentileScored 2026-11-07
Fix No fix listed No fixed version in the sources yet

SSVC decision points

Not available: CISA has not published SSVC decision points for this record.

Affected products

VendorProductAffected versionsFixed inStatusSource
—OpenVPN 3 Core Library3.6 and 3.6.1—No fix listedCNA
  • OpenVPN 3 Core Library Vendor— Affected 3.6 and 3.6.1 Fixed in — No fix listed CNA

CPE configurations NVD · 2

CPEVersionsRoleVendor
cpe:2.3:a:openvpn:openvpn:3.6:*:*:*:*:*:*:*3.6VulnerableOpenVPN
cpe:2.3:a:openvpn:openvpn:3.6.1:*:*:*:*:*:*:*3.6.1VulnerableOpenVPN
  • cpe:2.3:a:openvpn:openvpn:3.6:*:*:*:*:*:*:* Versions 3.6 Vulnerable ·OpenVPN
  • cpe:2.3:a:openvpn:openvpn:3.6.1:*:*:*:*:*:*:* Versions 3.6.1 Vulnerable ·OpenVPN

Remediation

No fixed version listed by the sources yet.

Vendor assessments

Red Hat

Red Hat's page for this CVE →

Not affected: 1 product
  • Red Hat

Timeline

  1. 2026-10-02 Threatist record created from CVE-2021-3547
  2. 2026-10-03 Alias added: GHSA-2cgw-c87g-ww8q

References

Patch 1

Advisory 1

  • TI-2014-04453 Unquoted Windows search path vulnerability in the ptservice service prior to… CVSS 3.1MEDIUM 5.3
  • TI-2022-00467 Authentication bypass in OpenVPN CVSS 3.1CRITICAL 9.8
  • TI-2024-18509 Unrestricted file upload in OpenVPN 2 CVSS 3.1CRITICAL 9.8
  • TI-2024-16468 The interactive service in OpenVPN 2.6.9 and earlier allows the OpenVPN service pipe to… CVSS 3.1HIGH 7.5
  • TI-2023-25309 Use after free in OpenVPN 2 CVSS 3.1CRITICAL 9.8
  • TI-2024-05196 OpenVPN before 2.6.11 does not santize PUSH_REPLY messages properly which an attacker… CVSS 3.1CRITICAL 9.1
See all 48 →

Sources

This product uses the NVD API but is not endorsed or certified by the NVD. Sources and licences