Apache HTTP Server 2.0.47 and earlier allows local users to bypass .htaccess file restrictions, as specified in httpd.conf with directives such as Deny From All, by using an ErrorDocument directive. NOTE: the vendor has disputed this issue, since the .htaccess mechanism is only intended to restrict external web access, and a local user already has the privileges to perform the same operations without using ErrorDocument
Apache 1.4.x before 1.3.30, and 2.0.x before 2.0.49, when using multiple listening sockets on certain platforms, allows remote attackers to cause a denial of service (blocked new connections) via a "short-lived connection on a rarely-accessed listening socket."
The rotatelogs program on Apache before 1.3.28, for Windows and OS/2 systems, does not properly ignore certain control characters that are received over the pipe, which could allow remote attackers to cause a denial of service.
Apache 1.3 through 1.3.24, and Apache 2.0 through 2.0.36, allows remote attackers to cause a denial of service and possibly execute arbitrary code via a chunk-encoded HTTP request that causes Apache to use an incorrect size.
Apache for Win32 before 1.3.24, and 2.0.x before 2.0.34-beta, allows remote attackers to execute arbitrary commands via shell metacharacters (a | pipe character) provided as arguments to batch (.bat) or .cmd scripts, which are sent unfiltered to the shell interpreter, typically cmd.exe.
Apache WWW server 1.3.1 and earlier allows remote attackers to cause a denial of service (resource exhaustion) via a large number of MIME headers with the same name, aka the "sioux" vulnerability.