CVE-2021-41524 : Exploit Details and Defense Strategies

Apache HTTP Server allows external sources to cause a Denial of Service (DoS) due to a null pointer dereference vulnerability introduced in version 2.4.49 during HTTP/2 request processing.

Understanding CVE-2021-41524

What is CVE-2021-41524?

CVE-2021-41524 is a vulnerability in Apache HTTP Server that can be exploited by specially crafted HTTP/2 requests to trigger a null pointer dereference, potentially leading to a DoS attack.

The Impact of CVE-2021-41524

The vulnerability in CVE-2021-41524 can allow attackers to exploit a null pointer dereference issue in version 2.4.49 of the Apache HTTP Server, leading to a potential DoS attack.

Technical Details of CVE-2021-41524

Vulnerability Description

A null pointer dereference vulnerability was discovered in version 2.4.49 of Apache HTTP Server during HTTP/2 request processing, potentially allowing attackers to disrupt server functionality.

Affected Systems and Versions

Product: Apache HTTP Server
Vendor: Apache Software Foundation
Affected Version: 2.4.49

Exploitation Mechanism

Attackers can exploit this vulnerability by sending specially crafted HTTP/2 requests to the server, triggering the null pointer dereference issue.

Mitigation and Prevention

Immediate Steps to Take

Disable the HTTP/2 protocol to mitigate the risk of exploitation.

Long-Term Security Practices

Keep software up to date with patches and security updates.
Implement network and application firewalls to filter incoming traffic.

Patching and Updates

Ensure that the Apache HTTP Server is updated to a version that addresses the CVE-2021-41524 vulnerability.