Peter Valchev discovered a flaw in the way expat handled malformed UTF-8 sequences when processing XML files. Incorrect UTF-8 sequenced could cause expat to fail to properly detect end of input and continue reading behind the end of input buffer. This results in a crash once reading reaches unmapped memory.

Non-public upstream bug report: http://sourceforge.net/tracker/?func=detail&aid=1990430&groupid=10127&atid=110127

Contents of the report leaked via expat-bugs mailing list posts: http://mail.python.org/pipermail/expat-bugs/2009-January/002781.html

Upstream patch: http://expat.cvs.sourceforge.net/viewvc/expat/expat/lib/xmltokimpl.c?r1=1.13&r2=1.15

References: http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=551936 https://bugs.gentoo.org/showbug.cgi?id=280615

The logcookie function in modlogconfig.c in the modlogconfig module in the Apache HTTP Server before 2.4.8 allows remote attackers to cause a denial of service (segmentation fault and daemon crash) via a crafted cookie that is not properly handled during truncation.

The davxmlgetcdata function in main/util.c in the moddav module in the Apache HTTP Server before 2.4.8 does not properly remove whitespace characters from CDATA sections, which allows remote attackers to cause a denial of service (daemon crash) via a crafted DAV WRITE request.

apache. Multiple issues were addressed by updating to version 2.4.27.

apache. Multiple issues were addressed by updating to version 2.4.27.

apache. Multiple issues were addressed by updating to version 2.4.27.

Apache HTTP Server, in all releases prior to 2.2.32 and 2.4.25, was liberal in the whitespace accepted from requests and sent in response lines and headers. Accepting these different behaviors represented a security concern when httpd participates in any chain of proxies or interacts with back-end application servers, either through modproxy or using conventional CGI mechanisms, and may result in request smuggling, response splitting and cache pollution.

apache. Multiple issues existed in Apache. These were addressed by updating Apache to version 2.4.25.

Apache HTTP Server 2.4.16 release fixes the following issue:

) SECURITY: CVE-2015-3183 (cve.mitre.org) core: Fix chunk header parsing defect. Remove aprbrigadeflatten(), buffering and duplicated code from the HTTPIN filter, parse chunks in a single pass with zero copy. Limit accepted chunk-size to 2^63-1 and be strict about chunk-ext authorized characters. [Graham Leggett, Yann Ylavic]

External References:

http://www.apache.org/dist/httpd/CHANGES2.4.16

Martin Holst Swende discovered a flaw in the way modheaders handled chunked requests. A remote attacker could use this flaw to bypass intended modheaders restrictions, allowing them to send requests to applications that include headers that should have been removed by modheaders.

Discussion and a possible patch is available from the following thread:

http://marc.info/?t=138219209900002&r=1&w=2

References:

http://martin.swende.se/blog/HTTPChunked.html

Quoting httpd 2.2 security page: http://httpd.apache.org/security/vulnerabilities22.html#2.2.15

moderate: modproxyajp DoS CVE-2010-0408

modproxyajp would return the wrong status code if it encountered an error causing a backend server to be put into an error state until the retry timeout expired. A remote attacker could send malicious requests to trigger this issue, resulting in a denial of service.

Affects: 2.2.0 - 2.2.14

Upstream commit: http://svn.apache.org/viewvc?view=revision&revision=917876

Quoting httpd 2.2 security page: http://httpd.apache.org/security/vulnerabilities22.html#2.2.15

low: Request header information leak CVE-2010-0434

A bug in the handling of headers in subrequests could lead to a reuse of memory. In a multithreaded MPM this could possibly cause an information leak from other requests being handled by a different thread.

Affects: 2.2.0 - 2.2.14

Upstream bug: https://issues.apache.org/bugzilla/showbug.cgi?id=48359

Upstream commits (2.2.x branch): http://svn.apache.org/viewvc?view=revision&revision=917867 http://svn.apache.org/viewvc?view=revision&revision=918427

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

modules/arch/win32/modisapi.c in modisapi 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 isapiunload 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."

Cross-site scripting (XSS) vulnerability in modautoindex.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.

Apache Portable Runtime (APR) is vulnerable to a denial of service, caused by an error in the aprfnmatch() function when processing specific patterns with the "" wildcard. A remote attacker could exploit this vulnerability to consume all available CPU and memory resources resulting in a denial of service.

Expat is vulnerable to a denial of service, caused by the improper handling of XML data by the big2toUtf8 function within the libexpat library. A remote attacker could exploit this vulnerability using a specially-crafted XML document containing malformed UTF-8 sequences that trigger a buffer over-read to cause the application to crash.

Possible CRLF injection allowing HTTP response splitting attacks for sites which use moduserdir. This issue was mitigated by changes made in 2.4.25 and 2.2.32 which prohibit CR or LF injection into the "Location" or other outbound header key or value. Fixed in Apache HTTP Server 2.4.25 (Affected 2.4.1-2.4.23). Fixed in Apache HTTP Server 2.2.32 (Affected 2.2.0-2.2.31).

Cross-site scripting (XSS) vulnerability in modstatus.c in the modstatus module in Apache HTTP Server (httpd), when ExtendedStatus is enabled and a public server-status page is used, allows remote attackers to inject arbitrary web script or HTML via unspecified vectors involving charsets with browsers that perform "charset detection" when the content-type is not specified.

Off-by-one error in the ldap scheme handling in the Rewrite module (modrewrite) in Apache 1.3 from 1.3.28, 2.0.46 and other versions before 2.0.59, and 2.2, when RewriteEngine is enabled, allows remote attackers to cause a denial of service (application crash) and possibly execute arbitrary code via crafted URLs that are not properly handled using certain rewrite rules.

An Uncontrolled Resource Consumption vulnerability in multiple products may allow an attacker to cause web service portal denial of service (DoS) via handling special crafted HTTP requests/responses in pieces slowly. Slow HTTP attacks are denial-of-service (DoS) attacks in which the attacker sends HTTP requests in pieces slowly, one at a time to a Web server. If an HTTP request is not complete, or if the transfer rate is very low, the server keeps its resources busy waiting for the rest of the data. When the server’s concurrent connection pool reaches its maximum, this creates a DoS. Slow HTTP attacks are easy to execute because they require only minimal resources from the attacker.

Cross-site scripting (XSS) vulnerability in modstatus in the Apache HTTP Server 2.2.0 through 2.2.6, 2.0.35 through 2.0.61, and 1.3.2 through 1.3.39, when the server-status page is enabled, allows remote attackers to inject arbitrary web script or HTML via unspecified vectors.

Cross-site request forgery (CSRF) vulnerability in the balancer-manager in modproxybalancer for Apache HTTP Server 2.2.x allows remote attackers to gain privileges via unspecified vectors.

Apache HTTP Server 2.0.x and 2.2.x does not sanitize the HTTP Method specifier header from an HTTP request when it is reflected back in a "413 Request Entity Too Large" error message, which might allow cross-site scripting (XSS) style attacks using web client components that can send arbitrary headers in requests, as demonstrated via an HTTP request containing an invalid Content-length value, a similar issue to CVE-2006-3918.

Cross-site scripting (XSS) vulnerability in the (1) modimap module in the Apache HTTP Server 1.3.0 through 1.3.39 and 2.0.35 through 2.0.61 and the (2) modimagemap module in the Apache HTTP Server 2.2.0 through 2.2.6 allows remote attackers to inject arbitrary web script or HTML via unspecified vectors.

The date handling code in modules/proxy/proxyutil.c (modproxy) in Apache 2.3.0, when using a threaded MPM, allows remote origin servers to cause a denial of service (caching forward proxy process crash) via crafted date headers that trigger a buffer over-read.

Apache httpd 1.3.37, 2.0.59, and 2.2.4 with the Prefork MPM module, allows local users to cause a denial of service by modifying the workerscore and processscore arrays to reference an arbitrary process ID, which is sent a SIGUSR1 signal from the master process, aka "SIGUSR1 killer."

cacheutil.c in the modcache module in Apache HTTP Server (httpd), when caching is enabled and a threaded Multi-Processing Module (MPM) is used, allows remote attackers to cause a denial of service (child processing handler crash) via a request with the (1) s-maxage, (2) max-age, (3) min-fresh, or (4) max-stale Cache-Control headers without a value.

Cross-site scripting (XSS) vulnerability in proxyftp.c in the modproxyftp module in Apache 2.0.63 and earlier, and modproxyftp.c in the modproxyftp module in Apache 2.2.9 and earlier 2.2 versions, allows remote attackers to inject arbitrary web script or HTML via a wildcard in the last directory component in the pathname in an FTP URI.

The approxyhttpprocessresponse function in modproxyhttp.c in the modproxy module in the Apache HTTP Server 2.0.63 and 2.2.8 does not limit the number of forwarded interim responses, which allows remote HTTP servers to cause a denial of service (memory consumption) via a large number of interim responses.