CVE-2021-40516 Explained : Impact and Mitigation

WeeChat before 3.2.1 allows remote attackers to cause a denial of service (crash) via a crafted WebSocket frame that triggers an out-of-bounds read in plugins/relay/relay-websocket.c in the Relay plugin.

Understanding CVE-2021-40516

This CVE describes a vulnerability in WeeChat that could be exploited by remote attackers to cause a denial of service.

What is CVE-2021-40516?

WeeChat version before 3.2.1 is susceptible to a crash caused by a specially crafted WebSocket frame that can lead to an out-of-bounds read in the Relay plugin.

The Impact of CVE-2021-40516

The vulnerability allows remote attackers to crash the application, leading to a denial of service condition.

Technical Details of CVE-2021-40516

This section provides more in-depth technical insights into the CVE.

Vulnerability Description

The vulnerability in WeeChat before 3.2.1 allows for a crash to be triggered by a crafted WebSocket frame, inducing an out-of-bounds read in the Relay plugin.

Affected Systems and Versions

Affected Versions: WeeChat versions before 3.2.1
Affected Component: plugins/relay/relay-websocket.c in the Relay plugin

Exploitation Mechanism

The vulnerability can be exploited by sending a specifically crafted WebSocket frame to the vulnerable WeeChat application.

Mitigation and Prevention

These are the recommended steps to mitigate and prevent exploitation of CVE-2021-40516.

Immediate Steps to Take

Users should update WeeChat to version 3.2.1 or later to prevent exploitation.
Monitor official sources for security updates and apply patches promptly.

Long-Term Security Practices

Regularly update software to the latest versions to ensure security patches are in place.
Employ network monitoring to detect abnormal traffic or attack patterns.

Patching and Updates

Update WeeChat to version 3.2.1 or the latest available version to eliminate the vulnerability.