A vulnerability was found in the Apache HTTP Server. Insufficient escaping of user-supplied data in mod_ssl 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.

An access control bypass vulnerability was found in Apache httpd. The Apache HTTP Server with some mod_ssl configurations can bypass the access controls by trusted clients using TLS 1.3 session resumption. A client trusted to access one virtual host may be able to access another if SSLStrictSNIVHostCheck is not enabled on either host.

An HTTP session hijacking flaw was found in Apache httpd. In some mod_ssl configurations on Apache HTTP Server, an HTTP desynchronization attack allows a man-in-the-middle attacker to hijack an HTTP session via a TLS upgrade.