CVE-2020-11810

NameCVE-2020-11810
DescriptionAn issue was discovered in OpenVPN 2.4.x before 2.4.9. An attacker can inject a data channel v2 (P_DATA_V2) packet using a victim's peer-id. Normally such packets are dropped, but if this packet arrives before the data channel crypto parameters have been initialized, the victim's connection will be dropped. This requires careful timing due to the small time window (usually within a few seconds) between the victim client connection starting and the server PUSH_REPLY response back to the client. This attack will only work if Negotiable Cipher Parameters (NCP) is in use.
SourceCVE (at NVD; CERT, LWN, oss-sec, fulldisc, Red Hat, Ubuntu, Gentoo, SUSE bugzilla/CVE, GitHub advisories/code/issues, web search, more)
ReferencesDLA-2992-1

Vulnerable and fixed packages

The table below lists information on source packages.

Source PackageReleaseVersionStatus
openvpn (PTS)buster2.4.7-1+deb10u1fixed
bullseye2.5.1-3fixed
bookworm, bookworm (security)2.6.3-1+deb12u2fixed
trixie2.6.7-1fixed
sid2.6.9-1fixed

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

PackageTypeReleaseFixed VersionUrgencyOriginDebian Bugs
openvpnsourcejessie(not affected)
openvpnsourcestretch2.4.0-6+deb9u4DLA-2992-1
openvpnsourcebuster2.4.7-1+deb10u1
openvpnsource(unstable)2.4.9-1low

Notes

[jessie] - openvpn <not-affected> (Vulnerable code introduced in 2.4)
https://github.com/OpenVPN/openvpn/commit/37bc691e7d26ea4eb61a8a434ebd7a9ae76225ab

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