mod_ssl in Apache 2.0 up to 2.0.55, when configured with an SSL vhost with access control and a custom error 400 error page, allows remote attackers to cause a denial of service (application crash) via a non-SSL request to an SSL port, which triggers a NULL pointer dereference.

The byte-range filter in Apache 2.0 before 2.0.54 allows remote attackers to cause a denial of service (memory consumption) via an HTTP header with a large Range field.

Unknown vulnerability in Apache 2.0.51 prevents "the merging of the Satisfy directive," which could allow attackers to obtain access to restricted resources contrary to the specified authentication configuration.

The mod_ssl module in Apache 2.0.35 through 2.0.52, when using the "SSLCipherSuite" directive in directory or location context, allows remote clients to bypass intended restrictions by using any cipher suite that is allowed by the virtual host configuration.