Apache » Http Server : Security Vulnerabilities, CVEs, (Overflow)

Apache HTTP Server 2.4.53 and earlier may crash or disclose information due to a read beyond bounds in ap_strcmp_match() when provided with an extremely large input buffer. While no code distributed with the server can be coerced into such a call, third-party modules or lua scripts that use ap_strcmp_match() may hypothetically be affected.

The ap_rwrite() function in Apache HTTP Server 2.4.53 and earlier may read unintended memory if an attacker can cause the server to reflect very large input using ap_rwrite() or ap_rputs(), such as with mod_luas r:puts() function. Modules compiled and distributed separately from Apache HTTP Server that use the 'ap_rputs' function and may pass it a very large (INT_MAX or larger) string must be compiled against current headers to resolve the issue.

Out-of-bounds Write vulnerability in mod_sed of Apache HTTP Server allows an attacker to overwrite heap memory with possibly attacker provided data. This issue affects Apache HTTP Server 2.4 version 2.4.52 and prior versions.

If LimitXMLRequestBody is set to allow request bodies larger than 350MB (defaults to 1M) on 32 bit systems an integer overflow happens which later causes out of bounds writes. This issue affects Apache HTTP Server 2.4.52 and earlier.

A carefully crafted request body can cause a buffer overflow in the mod_lua multipart parser (r:parsebody() called from Lua scripts). The Apache httpd team is not aware of an exploit for the vulnerabilty though it might be possible to craft one. This issue affects Apache HTTP Server 2.4.51 and earlier.

In Apache HTTP Server versions 2.4.0 to 2.4.46 a specially crafted SessionHeader sent by an origin server could cause a heap overflow

Apache HTTP server 2.4.32 to 2.4.44 mod_proxy_uwsgi info disclosure and possible RCE

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.

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.

In Apache httpd 2.2.x before 2.2.33 and 2.4.x before 2.4.26, mod_mime can read one byte past the end of a buffer when sending a malicious Content-Type response header.

The handle_headers function in mod_proxy_fcgi.c in the mod_proxy_fcgi module in the Apache HTTP Server 2.4.10 allows remote FastCGI servers to cause a denial of service (buffer over-read and daemon crash) via long response headers.

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_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.

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 big2_toUtf8 function in lib/xmltok.c in libexpat in Expat 2.0.1, as used in the XML-Twig module for Perl, allows context-dependent attackers to cause a denial of service (application crash) via an XML document with malformed UTF-8 sequences that trigger a buffer over-read, related to the doProlog function in lib/xmlparse.c, a different vulnerability than CVE-2009-2625 and CVE-2009-3720.

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.

Buffer overflow in htdigest in Apache 2.0.52 may allow attackers to execute arbitrary code via a long realm argument. NOTE: since htdigest is normally only locally accessible and not setuid or setgid, there are few attack vectors which would lead to an escalation of privileges, unless htdigest is executed from a CGI program. Therefore this may not be a vulnerability.

Off-by-one error in the mod_ssl Certificate Revocation List (CRL) verification callback in Apache, when configured to use a CRL, allows remote attackers to cause a denial of service (child process crash) via a CRL that causes a buffer overflow of one null byte.

Buffer overflow in the get_tag function in mod_include for Apache 1.3.x to 1.3.32 allows local users who can create SSI documents to execute arbitrary code as the apache user via SSI (XSSI) documents that trigger a length calculation error.

Buffer overflow in Apache 2.0.50 and earlier allows local users to gain apache privileges via a .htaccess file that causes the overflow during expansion of environment variables.

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.

Heap-based buffer overflow in proxy_util.c for mod_proxy in Apache 1.3.25 to 1.3.31 allows remote attackers to cause a denial of service (process crash) and possibly execute arbitrary code via a negative Content-Length HTTP header field, which causes a large amount of data to be copied.

Stack-based buffer overflow in the ssl_util_uuencode_binary function in ssl_util.c for Apache mod_ssl, when mod_ssl is configured to trust the issuing CA, may allow remote attackers to execute arbitrary code via a client certificate with a long subject DN.

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.