CVE-2020-36406 Explained : Impact and Mitigation

uWebSockets 18.11.0 and 18.12.0 has a stack-based buffer overflow vulnerability in uWS::TopicTree::trimTree, which can be exploited through uWS::TopicTree::unsubscribeAll. The vendor's stance on the severity of this issue is disputed.

Understanding CVE-2020-36406

This CVE involves a stack-based buffer overflow vulnerability in uWebSockets versions 18.11.0 and 18.12.0.

What is CVE-2020-36406?

The vulnerability exists in the uWS::TopicTree::trimTree function, which is called from uWS::TopicTree::unsubscribeAll, allowing for a stack-based buffer overflow.

The Impact of CVE-2020-36406

The vendor considers this a minor issue or not an issue at all, suggesting that developers should prevent the accumulation of a large number of triggered topics to mitigate the risk.

Technical Details of CVE-2020-36406

This section provides more technical insights into the vulnerability.

Vulnerability Description

The vulnerability is a stack-based buffer overflow in uWS::TopicTree::trimTree, triggered by uWS::TopicTree::unsubscribeAll.

Affected Systems and Versions

Product: Not applicable
Vendor: Not applicable
Versions: 18.11.0 and 18.12.0 are affected.

Exploitation Mechanism

The vulnerability can be exploited by allowing a large number of triggered topics to accumulate, leading to a stack-based buffer overflow.

Mitigation and Prevention

Protecting systems from CVE-2020-36406 requires immediate actions and long-term security practices.

Immediate Steps to Take

Monitor and limit the number of triggered topics in applications using uWebSockets.
Implement input validation to prevent buffer overflows.

Long-Term Security Practices

Regularly update uWebSockets to patched versions.
Follow secure coding practices to minimize the risk of buffer overflows.
Conduct security assessments and code reviews to identify and address vulnerabilities.
Stay informed about security advisories and updates from uWebSockets.

Patching and Updates

Apply patches provided by uWebSockets to address the stack-based buffer overflow vulnerability.