Apache HTTP Server: mod_ssl TLS upgrade attack
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.
01
describes (1)
Related CVEs.
| ID | severity | exploitable | ||
|---|---|---|---|---|
| CVE-2025-49812US | — | Exploit | ||
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… | ||||
02
references
External citations — patches, advisories, analysis.
- http://www.openwall.com/lists/oss-security/2025/07/09/3WEB
- http://www.openwall.com/lists/oss-security/2025/07/10/2WEB
- http://www.openwall.com/lists/oss-security/2025/07/10/9WEB
- https://httpd.apache.org/security/vulnerabilities_24.htmlADVISORY
- https://lists.debian.org/debian-lts-announce/2025/08/msg00009.htmlWEB
- https://nvd.nist.gov/vuln/detail/CVE-2025-49812WEB
scry
Advisories like this name the exposed products attackers go after on your perimeter. See what is exposed on your perimeter with a free passive scan.
Free scan