phpBB: Multiple vulnerabilities — GLSA 200503-02

Several vulnerabilities allow remote attackers to gain phpBB administrator rights or expose and manipulate sensitive data.

Affected Packages

www-apps/phpBB on all architectures
Affected versions < 2.0.13
Unaffected versions >= 2.0.13

Background

phpBB is an Open Source bulletin board package.

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

Release Date
March 01, 2005

Latest Revision
March 01, 2005: 01

Severity
normal

Exploitable
local and remote

Bugzilla entries