phpBB: Multiple vulnerabilities
Gentoo Linux Security Advisory
||GLSA 200503-02 / phpbb
||March 01, 2005
||March 01, 2005: 01
||local and remote
All supported architectures
Several vulnerabilities allow remote attackers to gain phpBB administrator
rights or expose and manipulate sensitive data.
phpBB is an Open Source bulletin board package.
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
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.
There is no known workaround at this time.
All phpBB users should upgrade to the latest available version:
Code Listing 3.1: Resolution
# emerge --sync
# emerge --ask --oneshot --verbose ">=www-apps/phpBB-2.0.13"