DescriptionOpenVPN 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.
SourceCVE (at NVD; CERT, LWN, oss-sec, fulldisc, bugtraq, EDB, Metasploit, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, Mageia, GitHub code/issues, web search, more)
NVD severitymedium
Debian Bugs324167

Vulnerable and fixed packages

The table below lists information on source packages.

Source PackageReleaseVersionStatus
openvpn (PTS)jessie (security), jessie2.3.4-5+deb8u2fixed
stretch (security)2.4.0-6+deb9u1fixed
bullseye, sid, buster2.4.7-1fixed

The information below is based on the following data on fixed versions.

PackageTypeReleaseFixed VersionUrgencyOriginDebian Bugs

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