Critical RCE Vulnerability in Apache HTTP Server (CVE-2024-38476)

Critical RCE Vulnerability in Apache HTTP Server (CVE-2024-38476)

A new critical vulnerability has been discovered in Apache HTTP Server that allows remote code execution. This CVE affects millions of web servers worldwide and requires immediate attention.

Vulnerability Details

CVE ID: CVE-2024-38476
CVSS Score: 9.8 (Critical)
Affected Versions: Apache HTTP Server 2.4.0 - 2.4.58
Attack Vector: Network
Authentication Required: None

Technical Analysis

The vulnerability exists in the mod_rewrite module when processing malformed HTTP requests. An attacker can craft a specially designed request that bypasses input validation and executes arbitrary code on the target server.

Exploitation Process

  1. Initial Request: Attacker sends malformed HTTP request
  2. Bypass Validation: Request bypasses mod_rewrite filters
  3. Code Injection: Malicious payload gets executed
  4. System Compromise: Full server control achieved
# Example vulnerable request pattern
GET /vulnerable-endpoint HTTP/1.1
Host: target.com
X-Rewrite-URL: /../../bin/sh
Content-Length: 0

Impact Assessment

  • Remote Code Execution with web server privileges
  • Data Breach potential for sensitive information
  • Service Disruption through DoS attacks
  • Lateral Movement within network infrastructure

Mitigation Strategies

Immediate Actions

  1. Update Apache to version 2.4.59 or later
  2. Disable mod_rewrite if not essential
  3. Implement WAF rules to block malicious requests
  4. Monitor logs for exploitation attempts

Long-term Security

  • Regular security updates
  • Network segmentation
  • Principle of least privilege
  • Continuous monitoring

Detection Methods

# Check Apache version
httpd -v

# Search for exploitation attempts in logs
grep -i "X-Rewrite-URL" /var/log/apache2/access.log

# Monitor for suspicious patterns
tail -f /var/log/apache2/error.log | grep -i "rewrite"

Conclusion

This vulnerability demonstrates the critical importance of keeping web servers updated. Organizations should prioritize patching and implement defense-in-depth strategies to protect against such threats.

Recommendation: Update immediately and review your security posture to prevent similar vulnerabilities from being exploited.

Stay updated with the latest security advisories and always test patches in a staging environment before production deployment.