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 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.

Memory leak in the apr_brigade_split_line function in buckets/apr_brigade.c in the Apache Portable Runtime Utility library (aka APR-util) before 1.3.10, as used in the mod_reqtimeout module in the Apache HTTP Server and other software, allows remote attackers to cause a denial of service (memory consumption) via unspecified vectors related to the destruction of an APR bucket.

Integer overflow in the ap_proxy_send_fb function in proxy/proxy_util.c in mod_proxy in the Apache HTTP Server before 1.3.42 on 64-bit platforms allows remote origin servers to cause a denial of service (daemon crash) or possibly execute arbitrary code via a large chunk size that triggers a heap-based buffer overflow.

The apr_strmatch_precompile function in strmatch/apr_strmatch.c in Apache APR-util before 1.3.5 allows remote attackers to cause a denial of service (daemon crash) via crafted input involving (1) a .htaccess file used with the Apache HTTP Server, (2) the SVNMasterURI directive in the mod_dav_svn module in the Apache HTTP Server, (3) the mod_apreq2 module for the Apache HTTP Server, or (4) an application that uses the libapreq2 library, which triggers a heap-based buffer underflow.

Tomcat 4.0 through 4.1.12, using mod_jk 1.2.1 module on Apache 1.3 through 1.3.27, allows remote attackers to cause a denial of service (desynchronized communications) via an HTTP GET request with a Transfer-Encoding chunked field with invalid values.

Cross site scripting vulnerabilities in Apache 1.3.0 through 1.3.11 allow remote attackers to execute script as other web site visitors via (1) the printenv CGI (printenv.pl), which does not encode its output, (2) pages generated by the ap_send_error_response function such as a default 404, which does not add an explicit charset, or (3) various messages that are generated by certain Apache modules or core code. NOTE: the printenv issue might still exist for web browsers that can render text/plain content types as HTML, such as Internet Explorer, but CVE regards this as a design limitation of those browsers, not Apache. The printenv.pl/acuparam vector, discloser on 20070724, is one such variant.