CVE-2022-29404 : Exploit Details and Defense Strategies

Apache HTTP Server 2.4.53 and earlier versions are impacted by a denial of service vulnerability due to a lack of default limit on possible input size in lua scripts. This vulnerability, reported by Ronald Crane from Zippenhop LLC, can be exploited by a malicious request to a lua script calling r:parsebody(0).

Understanding CVE-2022-29404

This section will delve into the details of the CVE-2022-29404 vulnerability in Apache HTTP Server.

What is CVE-2022-29404?

CVE-2022-29404 is a denial of service vulnerability in Apache HTTP Server versions 2.4.53 and earlier, allowing an attacker to cause a denial of service by sending a malicious request to a lua script.

The Impact of CVE-2022-29404

The impact of this vulnerability is considered low, but it can lead to a denial of service condition due to the absence of a default limit on the input size in lua scripts.

Technical Details of CVE-2022-29404

In this section, we will explore the technical aspects of CVE-2022-29404, including the vulnerability description, affected systems, versions, and the exploitation mechanism.

Vulnerability Description

The vulnerability in Apache HTTP Server arises from a lack of limit on the input size in lua scripts, specifically when a malicious request triggers the r:parsebody(0) function.

Affected Systems and Versions

The affected product is the Apache HTTP Server by the Apache Software Foundation with versions less than or equal to 2.4.53.

Exploitation Mechanism

To exploit CVE-2022-29404, an attacker needs to send a malicious request to a lua script that calls the r:parsebody(0) function, causing a denial of service.

Mitigation and Prevention

This section provides insights into mitigating the impact of CVE-2022-29404 and preventing similar vulnerabilities in the future.

Immediate Steps to Take

Apply the necessary patches and updates provided by Apache Software Foundation.
Monitor network traffic for any suspicious activities targeting lua scripts.

Long-Term Security Practices

Implement strong input validation mechanisms in lua scripts to prevent malicious inputs.
Regularly update and maintain the Apache HTTP Server to ensure the latest security fixes are in place.

Patching and Updates

Stay informed about security advisories and updates released by Apache Software Foundation to address CVE-2022-29404 and other potential vulnerabilities.