CVE-2020-11810 : What You Need to Know

OpenVPN 2.4.x before 2.4.9 allows an attacker to disrupt a victim's connection by injecting a specific data channel packet. This requires precise timing and can lead to connection drops.

Understanding CVE-2020-11810

This CVE involves a vulnerability in OpenVPN that can be exploited to disrupt connections.

What is CVE-2020-11810?

An attacker can inject a data channel v2 packet using a victim's peer-id in OpenVPN 2.4.x before 2.4.9. If the packet arrives before crypto parameters are initialized, the victim's connection will be dropped.

The Impact of CVE-2020-11810

Successful exploitation can lead to connection disruptions for victims using OpenVPN 2.4.x before 2.4.9.
The attack requires precise timing due to a small time window between the client connection initiation and server response.
This attack is only effective when Negotiable Cipher Parameters (NCP) are in use.

Technical Details of CVE-2020-11810

This section provides more technical insights into the vulnerability.

Vulnerability Description

The vulnerability allows an attacker to disrupt OpenVPN connections by injecting a specific data channel packet using the victim's peer-id.

Affected Systems and Versions

OpenVPN 2.4.x versions before 2.4.9 are affected by this vulnerability.

Exploitation Mechanism

The attacker needs to inject a data channel v2 packet with the victim's peer-id before crypto parameters are initialized to disrupt the connection.

Mitigation and Prevention

Protecting systems from CVE-2020-11810 requires immediate actions and long-term security practices.

Immediate Steps to Take

Update OpenVPN to version 2.4.9 or newer to mitigate the vulnerability.
Monitor network traffic for any suspicious activities that could indicate an ongoing attack.

Long-Term Security Practices

Regularly update and patch OpenVPN to ensure the latest security fixes are in place.
Implement network segmentation and access controls to limit the impact of potential attacks.

Patching and Updates

Stay informed about security updates and patches released by OpenVPN to address vulnerabilities like CVE-2020-11810.