CVE-2020-20813

Publication date 22 August 2023

Last updated 28 July 2025

Ubuntu priority

Cvss 3 Severity Score

Description

Control Channel in OpenVPN 2.4.7 and earlier allows remote attackers to cause a denial of service via crafted reset packet.

Read the notes from the security team

Status

Show unmaintained releases

Package	Ubuntu Release	Status
openvpn	25.04 plucky	Ignored see notes
	24.10 oracular	Ignored end of life, was deferred
	24.04 LTS noble	Ignored see notes
	23.10 mantic	Ignored end of life, was deferred
	23.04 lunar	Ignored end of life, was deferred
	22.04 LTS jammy	Ignored see notes
	20.04 LTS focal	Ignored see notes
	18.04 LTS bionic	Ignored see notes
	16.04 LTS xenial	Ignored see notes
	14.04 LTS trusty	Ignored see notes

Notes

mdeslaur

There are no details about this issue as of 2024-01-18

After reaching out to upstream, it doesn’t seem to be a CVE they issued or managed. Upstream pointed to some mentions in a chinese blog referring to about reflection attacks using OpenVPN and pointed to those being also independently reported and fixed as CVE-2021-4234 (Most relevant commit ids are b36471148 and 93d8d9231)

Severity score breakdown

Parameter	Value
Base score	7.5 · High
Attack vector	Network
Attack complexity	Low
Privileges required	None
User interaction	None
Scope	Unchanged
Confidentiality	None
Integrity impact	None
Availability impact	High
Vector	CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H