The dbm and shm session cache code in modssl before 2.8.7-1.3.23, and Apache-SSL before 1.3.22+1.46, does not properly initialize memory using the i2dSSLSESSION function, which allows remote attackers to use a buffer overflow to execute arbitrary code via a large client certificate that is signed by a trusted Certificate Authority (CA), which produces a large serialized session.

Format string vulnerability in the modproxy hook functions function in sslenginelog.c in modssl before 2.8.19 for Apache before 1.3.31 may allow remote attackers to execute arbitrary messages via format string specifiers in certain log messages for HTTPS that are handled by the ssllog function.