SB2020042461 - Fedora EPEL 8 update for openvpn

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Main Vulnerability Database SB2020042461

SB2020042461 - Fedora EPEL 8 update for openvpn

Published: April 24, 2020 Updated: April 25, 2025

Security Bulletin ID SB2020042461
Severity
Low
Patch available
YES
Number of vulnerabilities 1
Exploitation vector Remote access
Highest impact Denial of service

Breakdown by Severity

Low 100%
  • Low
  • Medium
  • High
  • Critical

Description

This security bulletin contains information about 1 security vulnerability.


1) Resource management error (CVE-ID: CVE-2020-11810)

The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.

The vulnerability exists due to improper management of internal resources within the application that allows a timing attack to be carried out against OpenVPN clients.

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.


Remediation

Install update from vendor's website.

References