CVE-2020-15078

Severity: high (CVSS 7.5 v3.1)
Exploited in the wild: not listed in CISA KEV
EPSS: 4.9% probability of exploitation in the next 30 days
Public exploit or detection template: none known
Published: 2021-04-26 · updated 2026-06-17
Weakness: CWE-305

Description

OpenVPN 2.5.1 and earlier versions allows a remote attackers to bypass authentication and access control channel data on servers configured with deferred authentication, which can be used to potentially trigger further information leaks.

Affected products

Canonical Ubuntu Linux: 18.04, 20.04, 20.10, 21.04
Debian Linux: 9.0
Fedoraproject Fedora: 32, 33, 34
OpenVPN: before 2.4.11; from 2.5.0 before 2.5.2 — fixed in 2.4.11, 2.5.2

How to fix

Upgrade to a fixed version: OpenVPN 2.4.11, 2.5.2. Check the vendor advisory for mitigations.

References

https://community.openvpn.net/openvpn/wiki/CVE-2020-15078
https://community.openvpn.net/openvpn/wiki/SecurityAnnouncements
https://lists.debian.org/debian-lts-announce/2022/05/msg00002.html
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/GJUXEYHUPREEBPX23VPEKMFXUPVO3PMU/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/JGEGLC4YGBDN5CGHTNWN2GH6DJJA36T2/
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/PLDB3OBQ3AODYYRN7NRCABV6I4AUFAT6/
https://security.gentoo.org/glsa/202105-25
https://usn.ubuntu.com/usn/usn-4933-1
https://community.openvpn.net/openvpn/wiki/CVE-2020-15078
https://community.openvpn.net/openvpn/wiki/SecurityAnnouncements
https://lists.debian.org/debian-lts-announce/2022/05/msg00002.html
https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/GJUXEYHUPREEBPX23VPEKMFXUPVO3PMU/

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