CVE-2024-47252: Apache HTTP Server: mod_ssl error log variable escaping

[Eric Covener <covener () apache org>]

Severity: low 

Affected versions:

- Apache HTTP Server 2.4 through 2.4.63

Description:

Insufficient escaping of user-supplied data in mod_ssl in Apache HTTP Server 2.4.63 and earlier allows an untrusted 
SSL/TLS client to insert escape characters into log files in some configurations.

In a logging configuration where CustomLog is used with "%{varname}x" or "%{varname}c" to log variables provided by 
mod_ssl such as SSL_TLS_SNI, no escaping is performed by either mod_log_config or mod_ssl and unsanitized data provided 
by the client may appear in log files.

Credit:

John Runyon (finder)

References:

https://httpd.apache.org/security/vulnerabilities_24.html
https://httpd.apache.org/
https://www.cve.org/CVERecord?id=CVE-2024-47252

Timeline:

2024-09-18: reported
2025-07-07: 2.4.x revision 1927042