CVE-2005-2531

Severity: medium (CVSS 5.0 v2.0)
Exploited in the wild: not listed in CISA KEV
EPSS: 2.0% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2005-08-24 · updated 2026-06-16

Description

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.

Affected products

OpenVPN: 2.0, 2.0.1_rc1, 2.0.1_rc2, 2.0.1_rc3, 2.0.1_rc4, 2.0.1_rc5 (+68)

References

http://openvpn.net/changelog.html
http://secunia.com/advisories/16463
http://secunia.com/advisories/17103
http://www.debian.org/security/2005/dsa-851
http://www.mandriva.com/security/advisories?name=MDKSA-2005:145
http://www.novell.com/linux/security/advisories/2005_20_sr.html
http://www.securityfocus.com/bid/14605
http://openvpn.net/changelog.html
http://secunia.com/advisories/16463
http://secunia.com/advisories/17103
http://www.debian.org/security/2005/dsa-851
http://www.mandriva.com/security/advisories?name=MDKSA-2005:145

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