CVE-2020-11077 : Vulnerability Insights and Analysis

In Puma (RubyGem) before 4.3.5 and 3.12.6, a client could smuggle a request through a proxy, causing the proxy to send a response back to another unknown client. This vulnerability has been fixed in Puma 3.12.6 and Puma 4.3.5.

Understanding CVE-2020-11077

This CVE involves HTTP smuggling via the Transfer-Encoding header in Puma.

What is CVE-2020-11077?

CVE-2020-11077 is a vulnerability in Puma that allows a client to manipulate a proxy server, potentially leading to responses being sent to unintended clients.

The Impact of CVE-2020-11077

CVSS Base Score: 6.8 (Medium)
Attack Vector: Network
Integrity Impact: High
Scope: Changed
This vulnerability could result in a client receiving responses meant for another client, impacting data integrity.

Technical Details of CVE-2020-11077

This section provides more technical insights into the vulnerability.

Vulnerability Description

The vulnerability allows a client to smuggle a request through a proxy, causing the proxy to send a response to an unintended client.

Affected Systems and Versions

Affected Versions: Puma < 3.12.6, Puma >= 4.0.0, < 4.3.5
Affected Systems: Puma RubyGem

Exploitation Mechanism

A client manipulates a proxy server to send responses to unintended clients.

Mitigation and Prevention

Protecting systems from CVE-2020-11077 requires immediate actions and long-term security practices.

Immediate Steps to Take

Update Puma to version 3.12.6 or 4.3.5 to mitigate the vulnerability.
Monitor network traffic for any suspicious activities.

Long-Term Security Practices

Implement secure coding practices to prevent similar vulnerabilities.
Regularly update and patch software to address known security issues.
Conduct security audits to identify and address potential vulnerabilities.
Educate users and administrators about secure practices.

Patching and Updates

Apply patches provided by Puma to fix the vulnerability.
Stay informed about security advisories and updates from Puma.