CVE-2019-15892 : Vulnerability Insights and Analysis

A vulnerability has been found in versions of Varnish Cache prior to 6.0.4 LTS, as well as 6.1.x and 6.2.x versions prior to 6.2.1. This vulnerability arises from a failure in parsing HTTP/1 requests, which can be exploited by an external attacker to trigger an assert statement, leading to a Denial of Service (DoS) attack.

Understanding CVE-2019-15892

This CVE identifies a security issue in Varnish Cache versions that could allow a remote attacker to cause a Denial of Service (DoS) attack.

What is CVE-2019-15892?

CVE-2019-15892 is a vulnerability in Varnish Cache versions before 6.0.4 LTS, 6.1.x, and 6.2.x before 6.2.1, caused by a failure in parsing HTTP/1 requests.

The Impact of CVE-2019-15892

The vulnerability allows an external attacker to trigger an assert statement, leading to an automatic system restart with a cleared cache, resulting in a Denial of Service (DoS) attack.

Technical Details of CVE-2019-15892

This section provides more technical insights into the vulnerability.

Vulnerability Description

An issue in Varnish Cache versions before 6.0.4 LTS, 6.1.x, and 6.2.x before 6.2.1 allows a remote attacker to trigger an assert by sending crafted HTTP/1 requests, causing an automatic restart with a clean cache, facilitating a Denial of Service attack.

Affected Systems and Versions

Varnish Cache versions prior to 6.0.4 LTS
Varnish Cache 6.1.x versions
Varnish Cache 6.2.x versions prior to 6.2.1

Exploitation Mechanism

The vulnerability is exploited by sending specially crafted HTTP/1 requests to the affected Varnish Cache versions, triggering an assert statement that leads to a system restart and a DoS attack.

Mitigation and Prevention

Protecting systems from CVE-2019-15892 requires immediate actions and long-term security practices.

Immediate Steps to Take

Update Varnish Cache to version 6.0.4 LTS, 6.1.0, or 6.2.1 to mitigate the vulnerability.
Monitor network traffic for any suspicious activity that could indicate an ongoing attack.

Long-Term Security Practices

Regularly update software and apply security patches to prevent known vulnerabilities.
Implement network security measures to detect and block malicious traffic.
Educate users and administrators about safe browsing practices and security best practices.

Patching and Updates

Ensure that Varnish Cache is regularly updated to the latest secure version to prevent exploitation of known vulnerabilities.