Apache HTTP Server

Apache HTTP Server: mod_md unrestricted OCSP response

Apache HTTP Server: Loop in `proxy_ftp_handler` in mod_proxy_ftp

Apache HTTP Server: mod_http2 memory corruption when file handles exhausted

Apache HTTP Server: mod_auth_digest DoS attack

In Apache HTTP Server 2.4.32-2.4.39, when mod_remoteip was configured to use a trusted intermediary proxy server using the "PROXY" protocol, a specially crafted PROXY header could trigger a stack buffer overflow or NULL pointer deference. This vulnerability could only be triggered by a trusted proxy and not by untrusted HTTP clients.

Multiple stack-based buffer overflows in (1) mod_alias and (2) mod_rewrite for Apache before 1.3.29 allow attackers to create configuration files to cause a denial of service (crash) or execute arbitrary code via a regular expression with more than 9 captures.

The shared memory scoreboard in the HTTP daemon for Apache 1.3.x before 1.3.27 allows any user running as the Apache UID to send a SIGUSR1 signal to any process as root, resulting in a denial of service (process kill) or possibly other behaviors that would not normally be allowed, by modifying the parent[].pid and parent[].last_rtime segments in the scoreboard.

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

The mod_deflate module in Apache httpd 2.2.11 and earlier compresses large files until completion even after the associated network connection is closed, which allows remote attackers to cause a denial of service (CPU consumption).

The stream_reqbody_cl function in mod_proxy_http.c in the mod_proxy module in the Apache HTTP Server before 2.3.3, when a reverse proxy is configured, does not properly handle an amount of streamed data that exceeds the Content-Length value, which allows remote attackers to cause a denial of service (CPU consumption) via crafted requests.

envvars (aka envvars-std) in the Apache HTTP Server before 2.4.2 places a zero-length directory name in the LD_LIBRARY_PATH, which allows local users to gain privileges via a Trojan horse DSO in the current working directory during execution of apachectl.

Cross-site scripting (XSS) vulnerability in the default error page of Apache 2.0 before 2.0.43, and 1.3.x up to 1.3.26, when UseCanonicalName is "Off" and support for wildcard DNS is present, allows remote attackers to execute script as other web page visitors via the Host: header, a different vulnerability than CAN-2002-1157.

Race condition in the mod_status module in the Apache HTTP Server before 2.4.10 allows remote attackers to cause a denial of service (heap-based buffer overflow), or possibly obtain sensitive credential information or execute arbitrary code, via a crafted request that triggers improper scoreboard handling within the status_handler function in modules/generators/mod_status.c and the lua_ap_scoreboard_worker function in modules/lua/lua_request.c.

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.

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.

A regression was found in the Red Hat Enterprise Linux 6.9 version of httpd 2.2.15-60, causing comments in the "Allow" and "Deny" configuration lines to be parsed incorrectly. A web administrator could unintentionally allow any client to access a restricted HTTP resource.

The default vhost configuration file in Puppet before 3.6.2 does not include the SSLCARevocationCheck directive, which might allow remote attackers to obtain sensitive information via a revoked certificate when a Puppet master runs with Apache 2.4.

Apache HTTP Server: CGI environment variable override

Apache HTTP Server: OOB Read in `merge_response_headers` can cause crash

Apache HTTP Server: multiple modules: HTTP response splitting forwarding malicious status line

The ap_get_mime_headers_core function in Apache httpd 2.0.49 allows remote attackers to cause a denial of service (memory exhaustion), and possibly an integer signedness error leading to a heap-based buffer overflow on 64 bit systems, via long header lines with large numbers of space or tab characters.

Off-by-one error in the apr_brigade_vprintf function in Apache APR-util before 1.3.5 on big-endian platforms allows remote attackers to obtain sensitive information or cause a denial of service (application crash) via crafted input.

Apache 2 before 2.0.47, and certain versions of mod_ssl for Apache 1.3, do not properly handle "certain sequences of per-directory renegotiations and the SSLCipherSuite directive being used to upgrade from a weak ciphersuite to a strong one," which could cause Apache to use the weak ciphersuite.

Apache HTTP Server: HTTP Response Splitting in multiple modules

Apache HTTP Server: 'RewriteCond expr' always evaluates to true in 2.4.64

Apache HTTP Server: source code disclosure with handlers configured via AddType

Multiple race conditions in suexec in Apache HTTP Server (httpd) 2.2.3 between directory and file validation, and their usage, allow local users to gain privileges and execute arbitrary code by renaming directories or performing symlink attacks. NOTE: the researcher, who is reliable, claims that the vendor disputes the issue because "the attacks described rely on an insecure server configuration" in which the user "has write access to the document root."

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.

mod_userdir CRLF injection

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.

The Apache HTTP Server 2.4.17 and 2.4.18, when mod_http2 is enabled, does not limit the number of simultaneous stream workers for a single HTTP/2 connection, which allows remote attackers to cause a denial of service (stream-processing outage) via modified flow-control windows.

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