It was discovered that phpBB contains a flaw in the session handling
code and a path disclosure bug. AnthraX101 discovered that phpBB allows
local users to read arbitrary files, if the "Enable remote avatars" and
"Enable avatar uploading" options are set (CAN-2005-0259). He also
found out that incorrect input validation in "usercp_avatar.php" and
"usercp_register.php" makes phpBB vulnerable to directory traversal
attacks, if the "Gallery avatars" setting is enabled (CAN-2005-0258).
Impact
======
Remote attackers can exploit the session handling flaw to gain phpBB
administrator rights. By providing a local and a remote location for an
avatar and setting the "Upload Avatar from a URL:" field to point to
the target file, a malicious local user can read arbitrary local files.
By inserting "/../" sequences into the "avatarselect" parameter, a
remote attacker can exploit the directory traversal vulnerability to
delete arbitrary files. A flaw in the "viewtopic.php" script can be
exploited to expose the full path of PHP scripts.
Workaround
==========
There is no known workaround at this time.
Resolution
==========
All phpBB users should upgrade to the latest available version:
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 (at) gentoo (dot) org [email concealed] or alternatively, you may file a bug at
http://bugs.gentoo.org.
License
=======
Copyright 2005 Gentoo Foundation, Inc; referenced text
belongs to its owner(s).
The contents of this document are licensed under the
Creative Commons - Attribution / Share Alike license.
Gentoo Linux Security Advisory GLSA 200503-02
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http://security.gentoo.org/
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Severity: Normal
Title: phpBB: Multiple vulnerabilities
Date: March 01, 2005
Bugs: #82955
ID: 200503-02
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Synopsis
========
Several vulnerabilities allow remote attackers to gain phpBB
administrator rights or expose and manipulate sensitive data.
Background
==========
phpBB is an Open Source bulletin board package.
Affected packages
=================
-------------------------------------------------------------------
Package / Vulnerable / Unaffected
-------------------------------------------------------------------
1 www-apps/phpBB < 2.0.13 >= 2.0.13
Description
===========
It was discovered that phpBB contains a flaw in the session handling
code and a path disclosure bug. AnthraX101 discovered that phpBB allows
local users to read arbitrary files, if the "Enable remote avatars" and
"Enable avatar uploading" options are set (CAN-2005-0259). He also
found out that incorrect input validation in "usercp_avatar.php" and
"usercp_register.php" makes phpBB vulnerable to directory traversal
attacks, if the "Gallery avatars" setting is enabled (CAN-2005-0258).
Impact
======
Remote attackers can exploit the session handling flaw to gain phpBB
administrator rights. By providing a local and a remote location for an
avatar and setting the "Upload Avatar from a URL:" field to point to
the target file, a malicious local user can read arbitrary local files.
By inserting "/../" sequences into the "avatarselect" parameter, a
remote attacker can exploit the directory traversal vulnerability to
delete arbitrary files. A flaw in the "viewtopic.php" script can be
exploited to expose the full path of PHP scripts.
Workaround
==========
There is no known workaround at this time.
Resolution
==========
All phpBB users should upgrade to the latest available version:
# emerge --sync
# emerge --ask --oneshot --verbose ">=www-apps/phpBB-2.0.13"
References
==========
[ 1 ] CAN-2005-0258
http://cve.mitre.org/cgi-bin/cvename.cgi?name=CAN-2005-0258
[ 2 ] CAN-2005-0259
http://cve.mitre.org/cgi-bin/cvename.cgi?name=CAN-2005-0259
[ 3 ] phpBB announcement
http://www.phpbb.com/phpBB/viewtopic.php?f=14&t=267563
Availability
============
This GLSA and any updates to it are available for viewing at
the Gentoo Security Website:
http://security.gentoo.org/glsa/glsa-200503-02.xml
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 (at) gentoo (dot) org [email concealed] or alternatively, you may file a bug at
http://bugs.gentoo.org.
License
=======
Copyright 2005 Gentoo Foundation, Inc; referenced text
belongs to its owner(s).
The contents of this document are licensed under the
Creative Commons - Attribution / Share Alike license.
http://creativecommons.org/licenses/by-sa/2.0
[ reply ]