modules/arch/win32/modisapi.c in modisapi in the Apache HTTP Server 2.0.37 through 2.0.63, 2.2.0 through 2.2.14, and 2.3.x before 2.3.7, when running on Windows, does not ensure that request processing is complete before calling isapiunload for an ISAPI .dll module, which allows remote attackers to execute arbitrary code via unspecified vectors related to a crafted request, a reset packet, and "orphaned callback pointers."

sslenginekernel.c in modssl before 2.8.24, when using "SSLVerifyClient optional" in the global virtual host configuration, does not properly enforce "SSLVerifyClient require" in a per-location context, which allows remote attackers to bypass intended access restrictions.

modcgid in Apache before 2.0.48, when using a threaded MPM, does not properly handle CGI redirect paths, which could cause Apache to send the output of a CGI program to the wrong client.