Updated: 2025-08-20 03:18:32.958503
Description:
In some mod_ssl configurations on Apache HTTP Server versions through to 2.4.63, an HTTP desynchronisation attack allows a man-in-the-middle attacker to hijack an HTTP session via a TLS upgrade. Only configurations using "SSLEngine optional" to enable TLS upgrades are affected. Users are recommended to upgrade to version 2.4.64, which removes support for TLS upgrade.
| Links | NIST | CIRCL | RHEL | Ubuntu |
| Severity | Score | |
|---|---|---|
| CVSS Version 2.x | NONE | 0.0 |
| CVSS Version 3.x | HIGH | 7.5 |
| OS name | Project name | Version | Score | Severity | Status | Errata | Last updated | Statement |
|---|---|---|---|---|---|---|---|---|
| Ubuntu 16.04 ELS | apache2 | 2.4.18 | 7.5 | HIGH | Released | CLSA-2025:1757014860 | 2025-09-04 21:32:01 | |
| Ubuntu 18.04 ELS | apache2 | 2.4.29 | 7.5 | HIGH | Released | CLSA-2025:1757014900 | 2025-09-04 21:32:00 |