The Apache HTTP Server 1.x and 2.x allows remote attackers to cause a denial of service (daemon outage) via partial HTTP requests, as demonstrated by Slowloris, related to the lack of the mod_reqtimeout module in versions before 2.2.15.

The mod_proxy module in the Apache HTTP Server 1.3.x through 1.3.42, 2.0.x through 2.0.64, and 2.2.x through 2.2.21, when the Revision 1179239 patch is in place, does not properly interact with use of (1) RewriteRule and (2) ProxyPassMatch pattern matches for configuration of a reverse proxy, which allows remote attackers to send requests to intranet servers via a malformed URI containing an @ (at sign) character and a : (colon) character in invalid positions. NOTE: this vulnerability exists because of an incomplete fix for CVE-2011-3368.

The ap_pregsub function in server/util.c in the Apache HTTP Server 2.0.x through 2.0.64 and 2.2.x through 2.2.21, when the mod_setenvif module is enabled, does not restrict the size of values of environment variables, which allows local users to cause a denial of service (memory consumption or NULL pointer dereference) via a .htaccess file with a crafted SetEnvIf directive, in conjunction with a crafted HTTP request header, related to (1) the "len +=" statement and (2) the apr_pcalloc function call, a different vulnerability than CVE-2011-3607.

Integer overflow in the ap_pregsub function in server/util.c in the Apache HTTP Server 2.0.x through 2.0.64 and 2.2.x through 2.2.21, when the mod_setenvif module is enabled, allows local users to gain privileges via a .htaccess file with a crafted SetEnvIf directive, in conjunction with a crafted HTTP request header, leading to a heap-based buffer overflow.

The mod_proxy module in the Apache HTTP Server 1.3.x through 1.3.42, 2.0.x through 2.0.64, and 2.2.x through 2.2.21 does not properly interact with use of (1) RewriteRule and (2) ProxyPassMatch pattern matches for configuration of a reverse proxy, which allows remote attackers to send requests to intranet servers via a malformed URI containing an initial @ (at sign) character.

modules/arch/win32/mod_isapi.c in mod_isapi 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 isapi_unload 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."

SQL injection vulnerability in mod_auth_mysql.c in the mod-auth-mysql (aka libapache2-mod-auth-mysql) module for the Apache HTTP Server 2.x, when configured to use a multibyte character set that allows a \ (backslash) as part of the character encoding, allows remote attackers to execute arbitrary SQL commands via unspecified inputs in a login request.

Cross-site scripting (XSS) vulnerability in Apache 2.2.6 and earlier allows remote attackers to inject arbitrary web script or HTML via UTF-7 encoded URLs that are not properly handled when displaying the 403 Forbidden error page.

Format string vulnerability in the mod_tcl module 1.0 for Apache 2.x allows context-dependent attackers to execute arbitrary code via format string specifiers that are not properly handled in a set_var function call in (1) tcl_cmds.c and (2) tcl_core.c.

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.

PHP 4.3.4 and earlier in Apache 1.x and 2.x (mod_php) can leak global variables between virtual hosts that are handled by the same Apache child process but have different settings, which could allow remote attackers to obtain sensitive information.

mod_disk_cache in Apache 2.0 through 2.0.49 stores client headers, including authentication information, on the hard disk, which could allow local users to gain sensitive information.

The mod_php module for the Apache HTTP Server allows local users with write access to PHP scripts to send signals to the server's process group and use the server's file descriptors, as demonstrated by sending a STOP signal, then intercepting incoming connections on the server's TCP port. NOTE: the PHP developer has disputed this vulnerability, saying "The opened file descriptors are opened by Apache. It is the job of Apache to protect them ... Not a bug in PHP.

Apache 2.0 through 2.0.39 on Windows, OS2, and Netware allows remote attackers to determine the full pathname of the server via (1) a request for a .var file, which leaks the pathname in the resulting error message, or (2) via an error message that occurs when a script (child process) cannot be invoked.

Directory traversal vulnerability in Apache 2.0 through 2.0.39 on Windows, OS2, and Netware allows remote attackers to read arbitrary files and execute commands via .. (dot dot) sequences containing \ (backslash) characters.

PHP, when installed with Apache and configured to search for index.php as a default web page, allows remote attackers to obtain the full pathname of the server via the HTTP OPTIONS method, which reveals the pathname in the resulting error message.

PHP for Windows, when installed on Apache 2.0.28 beta as a standalone CGI module, allows remote attackers to obtain the physical path of the php.exe via a request with malformed arguments such as /123, which leaks the pathname in the error message.