Critical Apache HTTP Server Security Update for Ubuntu 14.04 LTS: CVE-2024-38474 & CVE-2024-38475 Patched

 

Critical Apache HTTP Server security update for Ubuntu 14.04 LTS—patch CVE-2024-38474 & CVE-2024-38475 to prevent DoS & script injection. Learn how to secure your server now with ESM updates or migration steps.

Overview: Severe Denial-of-Service Vulnerability in Apache mod_rewrite

A critical security update has been issued for Apache HTTP Server on Ubuntu 14.04 LTS (Trusty Tahr). The vulnerability, tracked as CVE-2024-38474 and CVE-2024-38475, affects the mod_rewrite module and could allow attackers to:

✔ Execute unauthorized scripts in restricted directories

✔ Trigger denial-of-service (DoS) attacks

✔ Bypass security controls in certain configurations

This update follows USN-6885-5, addressing flaws initially patched in later Ubuntu releases. Administrators must apply the update immediately to mitigate risks.

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Detailed Vulnerability Analysis

What Went Wrong?

Security researcher Orange Tsai discovered that Apache’s mod_rewrite module mishandled substitution patterns, leading to:

• Path traversal risks (allowing script execution in non-URL-accessible directories)

• Server crashes under crafted rewrite rules

• Potential arbitrary code execution in edge cases

Some environments may require the UnsafeAllow3F flag to maintain compatibility while ensuring security.

Affected Systems

• Ubuntu 14.04 LTS (Trusty Tahr)

• Apache2 versions prior to 2.4.7-1ubuntu4.22+esm10

⚠️ Note: Ubuntu 14.04 LTS reached standard EOL in April 2019, but Ubuntu Pro subscribers still receive Extended Security Maintenance (ESM) updates.

 

How to Fix: Update Instructions

To patch this vulnerability:

1. For Ubuntu Pro Users:

   bash

   sudo apt update && sudo apt upgrade apache2

   Ensure your system updates to apache2 2.4.7-1ubuntu4.22+esm10.

2. For Non-Pro Users:
   Since Ubuntu 14.04 LTS is no longer supported without ESM, consider:

   • Upgrading to Ubuntu 20.04 LTS or later

   • Migrating to a supported web server (Nginx, LiteSpeed)

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Why This Update Matters for Security & Performance

✔ Prevents Remote Exploits – Stops attackers from abusing mod_rewrite misconfigurations.

✔ Ensures Server Stability – Mitigates crash risks under malicious requests.

✔ Maintains Compliance – Critical for enterprises adhering to CIS benchmarks or ISO 27001.

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Additional References & CVEs

• Ubuntu Security Notice (USN-6885-5) → View Here

• CVE-2024-38474 – Rewrite rule injection flaw

• CVE-2024-38475 – DoS via unsafe substitutions

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FAQ: Apache HTTP Server Security Patch

Q: Is Ubuntu 14.04 LTS still safe to use?

A: Only with Ubuntu Pro ESM. Otherwise, upgrade immediately.

Q: Does this affect other Linux distros?

A: Only if running an unpatched mod_rewrite in Apache. Check your vendor’s advisories.

Q: How do I check my Apache version?

A: Run:

bash

apache2 -v

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Final Recommendations

🚀 Action Steps:

1. Apply the patch now if using Ubuntu Pro.

2. Migrate to a newer LTS release if on standard Ubuntu 14.04.

3. Audit rewrite rules for unsafe patterns.

🔒 Need Expert Help? Consult a Linux security specialist for hardening.