CVE-2023-45802 : Vulnerability Insights and Analysis

This article provides detailed information about CVE-2023-45802, a vulnerability affecting Apache HTTP Server, related to HTTP/2 stream memory not being reclaimed immediately upon reset by a client.

Understanding CVE-2023-45802

CVE-2023-45802 is a moderate severity vulnerability impacting Apache HTTP Server, specifically concerning the handling of HTTP/2 stream resets initiated by a client. This flaw could lead to a scenario where memory resources are not promptly deallocated, potentially causing a memory leak.

What is CVE-2023-45802?

When a HTTP/2 stream is reset by a client, there is a delay in reclaiming the request's memory resources, leading to a gradual increase in memory footprint. If multiple resets are issued, the memory consumption could rise significantly, posing a risk of memory exhaustion.

The Impact of CVE-2023-45802

The vulnerability could allow a malicious client to exploit the server, keeping the connection open and occupying memory resources. In worst-case scenarios, this could result in denial-of-service (DoS) conditions due to memory exhaustion.

Technical Details of CVE-2023-45802

The vulnerability was discovered by security researchers Will Dormann and David Warren of Vul Labs. It was identified that upon reset of a HTTP/2 stream, memory resources were not promptly reclaimed, potentially leading to memory exhaustion.

Vulnerability Description

When a client triggers a HTTP/2 stream reset, the memory resources associated with the request are not immediately deallocated, creating a window for memory consumption to increase gradually.

Affected Systems and Versions

Apache HTTP Server versions up to and including 2.4.57 are affected by this vulnerability. It is crucial for users to upgrade to version 2.4.58 to mitigate the issue.

Exploitation Mechanism

An attacker can exploit this vulnerability by repeatedly resetting HTTP/2 streams, causing the server's memory footprint to grow continuously until the connection is closed or times out.

Mitigation and Prevention

It is imperative for users to take immediate actions to address CVE-2023-45802 to prevent potential exploitation and mitigate risks associated with memory consumption.

Immediate Steps to Take

Upgrade Apache HTTP Server to version 2.4.58, which includes a fix for the memory reclamation issue associated with HTTP/2 stream resets.

Long-Term Security Practices

Regularly monitor and apply security updates to the server software to address emerging vulnerabilities and enhance overall cybersecurity posture.

Patching and Updates

Stay informed about security advisories from Apache Software Foundation and apply patches promptly to ensure the server is protected from known vulnerabilities. Regularly check for updates and security bulletins to stay ahead of potential threats.