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How the CVE Works:
CVE-2025-49812 exploits a vulnerability in Apache HTTP Server (up to v2.4.63) when configured with SSLEngine optional, allowing TLS upgrades. A man-in-the-middle attacker can force an HTTP desynchronization attack by injecting malicious requests during the TLS handshake, leading to session hijacking. The server misinterprets request boundaries, enabling request smuggling. Apache 2.4.64 fixes this by removing TLS upgrade support.
DailyCVE Form:
Platform: Apache HTTP Server
Version: ≤ 2.4.63
Vulnerability: HTTP Desynchronization
Severity: Critical
Date: 07/29/2025
Prediction: Patch by 08/15/2025
What Undercode Say:
Check Apache version: httpd -v Test for vulnerable config: grep "SSLEngine optional" /etc/httpd/conf.d/ssl.conf Mitigation (pre-patch): SSLEngine on Disable optional TLS
How Exploit:
1. Intercept HTTP-to-HTTPS upgrade.
2. Inject malformed requests during handshake.
3. Trigger request smuggling.
Protection from this CVE:
- Upgrade to Apache 2.4.64.
- Disable
SSLEngine optional. - Use strict TLS policies.
Impact:
- Session hijacking.
- Data leakage.
- Request smuggling.
Sources:
Reported By: nvd.nist.gov
Extra Source Hub:
Undercode
