Resolving Apache 2.4.64 421 Misdirected Request Error on cPanel/CloudLinux Servers Print

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Overview: After the release of ea-apache24-2.4.64, many administrators on cPanel servers experienced a widespread issue causing websites behind reverse proxies (such as EA-Nginx or Cloudflare) to return the error:

421 Misdirected Request

This article provides a complete technical guide to understanding, reproducing, and resolving this issue by downgrading Apache and version-locking it to prevent recurrence, particularly in CloudLinux 8 environments.


⚠️ Issue Summary:

  • Error: 421 Misdirected Request

  • Cause: Apache 2.4.64 introduced stricter SSL/TLS handling to mitigate CVEs.

  • Impact: Servers using reverse proxies that omit SNI (Server Name Indication) in upstream connections fail to map virtual hosts correctly.

🔧 Affected Environments:

  • cPanel with EA-Nginx

  • Servers behind Cloudflare

  • CloudLinux (especially version 8/9)

  • Apache 2.4.64 (ea-apache24-2.4.64)


✅ Step-by-Step Solution

 

1. Check Current Apache Version

httpd -v
# or
rpm -q ea-apache24

Expected safe output:

ea-apache24-2.4.63-2.el8.cloudlinux.x86_64

2. If Website is Down and Version is 2.4.64 ❌

Downgrade Apache to 2.4.63:

dnf downgrade ea-apache24*

Then apply version lock:

dnf install python3-dnf-plugin-versionlock -y
rpm -q ea-apache24  # get exact version after downgrade

dnf versionlock add ea-apache24-2.4.63-2.el8.cloudlinux.x86_64

3. If Website is Working and Version is Already 2.4.63 ✅

Simply lock the version to prevent future upgrades:

dnf install python3-dnf-plugin-versionlock -y

dnf versionlock add ea-apache24-2.4.63-2.el8.cloudlinux.x86_64

4. Verify the Lock

dnf versionlock list | grep ea-apache24

Expected output:

ea-apache24-1:2.4.63-2.el8.cloudlinux.*

⏰ Optional: Schedule Automatic Unlock After 30 Days

Using at (One-time task):

dnf install at -y
systemctl enable --now atd
echo "dnf versionlock delete ea-apache24" | at now + 30 days

Using cron (fixed date):

0 3 25 8 * dnf versionlock delete ea-apache24

📊 Verification & Monitoring

To ensure your server remains unaffected:


🔗 Reference Links:


Conclusion: To maintain stability across web hosting environments using reverse proxies, system administrators should temporarily downgrade and lock Apache at version 2.4.63 until a cPanel patch resolves the 421 issue. This proactive step prevents outages and ensures client websites remain accessible and secure.

 


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