CVE-2019-20637 : Vulnerability Insights and Analysis

A vulnerability was found in Varnish Cache versions prior to 6.0.5 LTS, 6.1.x, 6.2.x before 6.2.2, and 6.3.x before 6.3.1, potentially leading to information leakage.

Understanding CVE-2019-20637

This CVE describes a vulnerability in Varnish Cache that could allow information disclosure during the handling of multiple client requests within the same connection.

What is CVE-2019-20637?

This vulnerability arises from a failure to properly clear a pointer between client requests within the same connection, potentially exposing sensitive data from previous requests or temporary headers.

The Impact of CVE-2019-20637

The vulnerability could result in information leakage from the connection workspace, including data structures linked to previous requests within the same connection or temporary headers related to the VCL.

Technical Details of CVE-2019-20637

This section provides more in-depth technical details about the vulnerability.

Vulnerability Description

The issue in Varnish Cache versions before 6.0.5 LTS, 6.1.x, 6.2.x before 6.2.2, and 6.3.x before 6.3.1 arises from the failure to clear a pointer between client requests within the same connection.

Affected Systems and Versions

Varnish Cache versions prior to 6.0.5 LTS
6.1.x and 6.2.x before 6.2.2
6.3.x before 6.3.1

Exploitation Mechanism

The vulnerability can be exploited by an attacker sending multiple client requests within the same connection to potentially access sensitive information.

Mitigation and Prevention

Protecting systems from CVE-2019-20637 requires immediate actions and long-term security practices.

Immediate Steps to Take

Update Varnish Cache to versions 6.0.5 LTS, 6.2.2, or 6.3.1 to mitigate the vulnerability.
Monitor network traffic for any suspicious activity that could indicate exploitation.

Long-Term Security Practices

Regularly update and patch software to address known vulnerabilities.
Implement network segmentation to limit the impact of potential breaches.

Patching and Updates

Apply patches provided by Varnish Cache to fix the vulnerability and enhance system security.