Apache HTTP Server any version

In Apache HTTP Server 2.4.0-2.4.39, a limited cross-site scripting issue was reported affecting the mod_proxy error page. An attacker could cause the link on the error page to be malformed and instead point to a page of their choice. This would only be exploitable where a server was set up with proxying enabled but was misconfigured in such a way that the Proxy Error page was displayed.

In Apache HTTP server 2.4.0 to 2.4.39, Redirects configured with mod_rewrite that were intended to be self-referential might be fooled by encoded newlines and redirect instead to an unexpected URL within the request URL.

In Apache HTTP Server 2.4.0 to 2.4.41, redirects configured with mod_rewrite that were intended to be self-referential might be fooled by encoded newlines and redirect instead to an an unexpected URL within the request URL.

Cross-site scripting (XSS) vulnerability in mod_autoindex.c in the Apache HTTP Server before 2.2.6, when the charset on a server-generated page is not defined, allows remote attackers to inject arbitrary web script or HTML via the P parameter using the UTF-7 charset. NOTE: it could be argued that this issue is due to a design limitation of browsers that attempt to perform automatic content type detection.

Open Redirect in oidc_validate_redirect_url()

XSS vulnerability when using OIDCPreservePost On in mod_auth_openidc

Apache HTTP Server: mod_proxy_ftp XSS

In Apache HTTP Server 2.4.17 to 2.4.34, by sending continuous, large SETTINGS frames a client can occupy a connection, server thread and CPU time without any connection timeout coming to effect. This affects only HTTP/2 connections. A possible mitigation is to not enable the h2 protocol.

A specially crafted request could have crashed the Apache HTTP Server prior to version 2.4.30, due to an out of bound access after a size limit is reached by reading the HTTP header. This vulnerability is considered very hard if not impossible to trigger in non-debug mode (both log and build level), so it is classified as low risk for common server usage.

When an HTTP/2 stream was destroyed after being handled, the Apache HTTP Server prior to version 2.4.30 could have written a NULL pointer potentially to an already freed memory. The memory pools maintained by the server make this vulnerability hard to trigger in usual configurations, the reporter and the team could not reproduce it outside debug builds, so it is classified as low risk.

Apache HTTP Server: HTTP/2 stream memory not reclaimed right away on RST

Hardcoded static IV and AAD with a reused key in AES GCM encryption in mod_auth_openidc

Improper Handling of Insufficient Privileges

Apache HTTP Server: escalation of privilege through expressions in .htaccess in multiple modules

Apache HTTP Server: DoS by Null pointer in websocket over HTTP/2

Apache HTTP Server: mod_userdir+suexec bypass via AllowOverride FileInfo

Apache HTTP Server: mod_proxy prior to 2.4.55 allows a backend to trigger HTTP response splitting

mod_proxy_wstunnel tunneling of non Upgraded connections

Unexpected URL matching with 'MergeSlashes OFF'

In Apache HTTP Server 2.4.0 to 2.4.41, mod_proxy_ftp may use uninitialized memory when proxying to a malicious FTP server.

A vulnerability was found in Apache HTTP Server 2.4.17 to 2.4.38. Using fuzzed network input, the http/2 request handling could be made to access freed memory in string comparison when determining the method of a request and thus process the request incorrectly.

A vulnerability was found in Apache HTTP Server 2.4.0 to 2.4.38. When the path component of a request URL contains multiple consecutive slashes ('/'), directives such as LocationMatch and RewriteRule must account for duplicates in regular expressions while other aspects of the servers processing will implicitly collapse them.

In Apache httpd 2.4.0 to 2.4.29, when mod_session is configured to forward its session data to CGI applications (SessionEnv on, not the default), a remote user may influence their content by using a "Session" header. This comes from the "HTTP_SESSION" variable name used by mod_session to forward its data to CGIs, since the prefix "HTTP_" is also used by the Apache HTTP Server to pass HTTP header fields, per CGI specifications.

IP address spoofing when proxying using mod_remoteip and mod_rewrite For configurations using proxying with mod_remoteip and certain mod_rewrite rules, an attacker could spoof their IP address for logging and PHP scripts. Note this issue was fixed in Apache HTTP Server 2.4.24 but was retrospectively allocated a low severity CVE in 2020.

read beyond bounds via ap_rwrite()

read beyond bounds in mod_isapi

Apache HTTP Server: mod_authn_socache crash

Apache HTTP Server: mod_proxy_ajp: Heap Buffer Over-Read Due to Missing Null-Termination Check (ajp_msg_get_string)

Apache HTTP Server: Off-by-one OOB reads in AJP getter functions

mod_rewrite.c in the mod_rewrite module in the Apache HTTP Server 2.2.x before 2.2.25 writes data to a log file without sanitizing non-printable characters, which might allow remote attackers to execute arbitrary commands via an HTTP request containing an escape sequence for a terminal emulator.

Directory traversal vulnerability in Apache HTTP Server and Tomcat 5.x before 5.5.22 and 6.x before 6.0.10, when using certain proxy modules (mod_proxy, mod_rewrite, mod_jk), allows remote attackers to read arbitrary files via a .. (dot dot) sequence with combinations of (1) "/" (slash), (2) "\" (backslash), and (3) URL-encoded backslash (%5C) characters in the URL, which are valid separators in Tomcat but not in Apache.

A memory leak in Apache 2.0 through 2.0.44 allows remote attackers to cause a denial of service (memory consumption) via large chunks of linefeed characters, which causes Apache to allocate 80 bytes for each linefeed.

The chunked transfer coding implementation in the Apache HTTP Server before 2.4.14 does not properly parse chunk headers, which allows remote attackers to conduct HTTP request smuggling attacks via a crafted request, related to mishandling of large chunk-size values and invalid chunk-extension characters in modules/http/http_filters.c.

The char_buffer_read function in the mod_ssl module for Apache 2.x, when using reverse proxying to an SSL server, allows remote attackers to cause a denial of service (segmentation fault).

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.

Apache webserver 2.0.52 and earlier allows remote attackers to cause a denial of service (CPU consumption) via an HTTP GET request with a MIME header containing multiple lines with a large number of space characters.

The mod_cgid module in the Apache HTTP Server before 2.4.10 does not have a timeout mechanism, which allows remote attackers to cause a denial of service (process hang) via a request to a CGI script that does not read from its stdin file descriptor.

A possible interaction between Apple MacOS X release 1.0 and Apache HTTP server allows remote attackers to cause a denial of service (crash) via a flood of HTTP GET requests to CGI programs, which generates a large number of processes.

A default configuration of Apache on Debian GNU/Linux sets the ServerRoot to /usr/doc, which allows remote users to read documentation files for the entire server.

test-cgi program allows an attacker to list files on the server.