CVE-2005-2531
OpenVPN before 2.0.1, when running with "verb 0" and without TLS authentication, does not...
OpenVPN before 2.0.1, when running with "verb 0" and without TLS authentication, does not properly flush the OpenSSL error queue when a client fails certificate authentication to the server and causes the error to be processed by the wrong client, which allows remote attackers to cause a denial of service (client disconnection) via a large number of failed authentication attempts.
Exploit likelihood
What each source reports
NVD Score used
OpenVPN before 2.0.1, when running with "verb 0" and without TLS authentication, does not properly flush the OpenSSL error queue when a client fails certificate authentication to the server and causes the error to be processed by the wrong client, which allows remote attackers to cause a denial of service (client disconnection) via a large number of failed authentication attempts.
- Record
CVE-2005-2531- CVSS 2.0
- 5.0 Medium
AV:N/AC:L/Au:N/C:N/I:N/A:P - Updated
- 2026-11-02
CVE List No score
OpenVPN before 2.0.1, when running with "verb 0" and without TLS authentication, does not properly flush the OpenSSL error queue when a client fails certificate authentication to the server and causes the error to be processed by the wrong client, which allows remote attackers to cause a denial of service (client disconnection) via a large number of failed authentication attempts.
- Record
CVE-2005-2531- Updated
- 2026-11-02
EUVDEUVD-2005-2532 No score
OpenVPN before 2.0.1, when running with "verb 0" and without TLS authentication, does not properly flush the OpenSSL error queue when a client fails certificate authentication to the server and causes the error to be processed by the wrong client, which allows remote attackers to cause a denial of service (client disconnection) via a large number of failed authentication attempts.
- Record
EUVD-2005-2532- Updated
- 2026-11-03
GitHub AdvisoriesGHSA-h572-qc5h-fc64 No score
OpenVPN before 2.0.1, when running with "verb 0" and without TLS authentication, does not...
OpenVPN before 2.0.1, when running with "verb 0" and without TLS authentication, does not properly flush the OpenSSL error queue when a client fails certificate authentication to the server and causes the error to be processed by the wrong client, which allows remote attackers to cause a denial of service (client disconnection) via a large number of failed authentication attempts.
- Record
GHSA-h572-qc5h-fc64- Updated
- 2026-11-02
OSV No score
OpenVPN before 2.0.1, when running with "verb 0" and without TLS authentication, does not properly flush the OpenSSL error queue when a client fails certificate authentication to the server and causes the error to be processed by the wrong client, which allows remote attackers to cause a denial of service (client disconnection) via a large number of failed authentication attempts.
- Record
CVE-2005-2531- Updated
- 2026-11-02
OSVDEBIAN-CVE-2005-2531 No score
OpenVPN before 2.0.1, when running with "verb 0" and without TLS authentication, does not properly flush the OpenSSL error queue when a client fails certificate authentication to the server and causes the error to be processed by the wrong client, which allows remote attackers to cause a denial of service (client disconnection) via a large number of failed authentication attempts.
- Record
DEBIAN-CVE-2005-2531- Updated
- 2026-11-02
Affected products
Affected packages
History
| Recorded | Changed | Sources |
|---|---|---|
| aliases | EUVD | |
| first indexed | CVE List, GitHub Advisories, NVD, OSV |
Dates are when Every CVE recorded each change. Upstream dates may differ.
In short
CVE-2005-2531 is a medium vulnerability (CVSS 5.0) in Openvpn, published August 24, 2005. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 1.97%, the 80th percentile. Fixed in openvpn 2.0.2-1.