Apache 2 before 2.0.47, and certain versions of mod_ssl for Apache 1.3, do not properly handle "certain sequences of per-directory renegotiations and the SSLCipherSuite directive being used to upgrade from a weak ciphersuite to a strong one," which could cause Apache to use the weak ciphersuite.

The prefork MPM in Apache 2 before 2.0.47 does not properly handle certain errors from accept, which could lead to a denial of service.

Vulnerability in the apr_psprintf function in the Apache Portable Runtime (APR) library for Apache 2.0.37 through 2.0.45 allows remote attackers to cause a denial of service (crash) and possibly execute arbitrary code via long strings, as demonstrated using XML objects to mod_dav, and possibly other vectors.

The authentication module for Apache 2.0.40 through 2.0.45 on Unix does not properly handle threads safely when using the crypt_r or crypt functions, which allows remote attackers to cause a denial of service (failed Basic authentication with valid usernames and passwords) when a threaded MPM is used.

Unknown vulnerability in filestat.c for Apache running on OS2, versions 2.0 through 2.0.45, allows unknown attackers to cause a denial of service via requests related to device names.