Gentoo Linux Advisory: Apache 2

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Gentoo Linux Security Advisory GLSA 200403-04

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http://security.gentoo.org

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Severity: Normal
Title: Multiple security vulnerabilities in Apache 2
Date: March 22, 2004
Bugs: #45206
ID: 200403-04

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Synopsis

A memory leak in mod_ssl allows a remote denial of service
attack against an SSL-enabled server via plain HTTP requests.
Another flaw was found when arbitrary client-supplied strings can
be written to the error log, allowing the exploit of certain
terminal emulators. A third flaw exists with the mod_disk_cache
module.

Background

The Apache HTTP Server Project is an effort to develop and
maintain an open-source HTTP server for modern operating systems.
The goal of this project is to provide a secure, efficient and
extensible server that provides services in tune with the current
HTTP standards.

Affected packages

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Description

Three vulnerabilities were found:

1. A memory leak in ssl_engine_io.c for mod_ssl in Apache 2.0.48
   and below allows remote attackers to cause a denial of service
   attack via plain HTTP requests to the SSL port of an SSL-enabled
   server.
2. Apache fails to filter terminal escape sequences from error
   logs that begin with the ASCII (0x1B) sequence and are followed by
   a series of arguments. If a remote attacker could inject escape
   sequences into an Apache error log, the attacker could take
   advantages of weaknesses in various terminal emulators, launching
   attacks against remote users including further denial of service
   attacks, file modification, and the execution of arbitrary
   commands.
3. The Apache mod_disk_cache has been found to be vulnerable to a
   weakness that allows attackers to gain access to authentication
   credentials through the issue of caching HTTP hop-by-hop headers
   which would contain plaintext user passwords. There is no available
   resolution for this issue yet.

Impact

No special privileges are required for these vulnerabilities. As
a result, all users are recommended to upgrade their Apache
installations.

Workaround

There is no immediate workaround; a software upgrade is
required. There is no workaround for the mod_disk_cache issue;
users are recommended to disable the feature on their servers until
a patched version is released.

Resolution

Users are urged to upgrade to Apache 2.0.49:

     # emerge sync
     # emerge -pv ">=net-www/apache-2.0.49"
     # emerge ">=net-www/apache-2.0.49"
     # ** IMPORTANT **
     # If you are migrating from Apache 2.0.48-r1 or earlier versions,
     # it is important that the following directories are removed.
     # The following commands should cause no data loss since these
     # are symbolic links.
     # rm /etc/apache2/lib /etc/apache2/logs /etc/apache2/modules
     # rm /etc/apache2/modules
     # ** ** ** ** **
     # ** ALSO NOTE **
     # Users who use mod_disk_cache should edit their Apache
     # configuration and disable mod_disk_cache.

References

[ 1 ] http://www.securityfocus.com/bid/9933/info/

[ 2 ] http://www.apache.org/dist/httpd/Announcement2.html

Concerns?

Security is a primary focus of Gentoo Linux and ensuring the
confidentiality and security of our users machines is of utmost
importance to us. Any security concerns should be addressed to
security@gentoo.org or
alternatively, you may file a bug at http://bugs.gentoo.org.