Apache 2, mod_dav: Multiple vulnerabilities

1. Gentoo Linux Security Advisory

Advisory Reference	GLSA 200409-21 / apache
Release Date	September 16, 2004
Latest Revision	December 30, 2007: 02
Impact	normal
Exploitable	remote

Package	Vulnerable versions	Unaffected versions	Architecture(s)
www-servers/apache	< 2.0.51	>= 2.0.51, < 2.0	All supported architectures
net-www/mod_dav	<= 1.0.3-r1	>= 1.0.3-r2	All supported architectures

Related bugreports: #62626, #63948, #64145

Synopsis

Several vulnerabilities have been found in Apache 2 and mod_dav for Apache 1.3 which could allow a remote attacker to cause a Denial of Service or a local user to get escalated privileges.

2. Impact Information

Background

The Apache HTTP server is one of most popular web servers on the internet. mod_ssl provides SSL v2/v3 and TLS v1 support for it and mod_dav is the Apache module for Distributed Authoring and Versioning (DAV).

Description

A potential infinite loop has been found in the input filter of mod_ssl (CAN-2004-0748) as well as a possible segmentation fault in the char_buffer_read function if reverse proxying to a SSL server is being used (CAN-2004-0751). Furthermore, mod_dav, as shipped in Apache httpd 2 or mod_dav 1.0.x for Apache 1.3, contains a NULL pointer dereference which can be triggered remotely (CAN-2004-0809). The third issue is an input validation error found in the IPv6 URI parsing routines within the apr-util library (CAN-2004-0786). Additionally a possible buffer overflow has been reported when expanding environment variables during the parsing of configuration files (CAN-2004-0747).

Impact

A remote attacker could cause a Denial of Service either by aborting a SSL connection in a special way, resulting in CPU consumption, by exploiting the segmentation fault in mod_ssl or the mod_dav flaw. A remote attacker could also crash a httpd child process by sending a specially crafted URI. The last vulnerabilty could be used by a local user to gain the privileges of a httpd child, if the server parses a carefully prepared .htaccess file.

3. Resolution Information

Workaround

There is no known workaround at this time.

Resolution

All Apache 2 users should upgrade to the latest version:

Code Listing 3.1: Resolution

# emerge sync
# emerge -pv ">=www-servers/apache-2.0.51"
# emerge ">=www-servers/apache-2.0.51"

All mod_dav users should upgrade to the latest version:

Code Listing 3.2: Resolution

# emerge sync
# emerge -pv ">=net-www/mod_dav-1.0.3-r2"
# emerge ">=net-www/mod_dav-1.0.3-r2"

4. References

Updated September 16, 2004

Summary: This is a Gentoo Linux Security Advisory

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