CVE-2018-1333 : Security Advisory and Response

A denial of service vulnerability in Apache HTTP Server due to worker exhaustion caused by manipulating HTTP/2 requests.

Understanding CVE-2018-1333

Crafted HTTP/2 requests led to worker exhaustion, causing denial of service. Resolved in Apache HTTP Server 2.4.34.

What is CVE-2018-1333?

By manipulating HTTP/2 requests, workers were allocated 60 seconds longer than needed, resulting in exhaustion and a denial of service.

The Impact of CVE-2018-1333

The vulnerability caused worker fatigue due to extended allocation, leading to a denial of service attack.

Technical Details of CVE-2018-1333

Affecting Apache HTTP Server, versions 2.4.18 to 2.4.30 and 2.4.33, the vulnerability allowed for worker exhaustion through crafted HTTP/2 requests.

Vulnerability Description

HTTP/2 requests manipulation led to worker exhaustion, causing denial of service.

Affected Systems and Versions

Apache HTTP Server versions 2.4.18 to 2.4.30 and 2.4.33 were impacted.

Exploitation Mechanism

Crafted HTTP/2 requests caused workers to be allocated extra time, resulting in exhaustion and denial of service.

Mitigation and Prevention

Immediate Steps to Take

Update Apache HTTP Server to version 2.4.34 to mitigate the vulnerability.
Monitor server logs for unusual HTTP/2 request patterns.

Long-Term Security Practices

Regularly update and patch Apache HTTP Server to prevent known vulnerabilities.
Implement network-level protections to detect and block malicious HTTP/2 requests.

Patching and Updates

Apply patches and updates provided by Apache Software Foundation to address CVE-2018-1333.