GLSA 200411-32: phpBB: Remote command execution

http://security.gentoo.org/

Severity:	high
Title:	phpBB: Remote command execution
Date:	11/24/2004
Bugs:	#71681
ID:	200411-32

Synopsis

phpBB contains a vulnerability which allows a remote attacker to execute arbitrary commands with the rights of the web server user.

Background

phpBB is an Open Source bulletin board package.

Affected packages

Package	Vulnerable	Unaffected	Architecture(s)
www-apps/phpbb	< 2.0.10	>= 2.0.11	All supported architectures

Description

phpBB contains a vulnerability in the highlighting code and several vulnerabilities in the username handling code.

Impact

An attacker can exploit the highlighting vulnerability to access the PHP exec() function without restriction, allowing them to run arbitrary commands with the rights of the web server user (for example the apache user). Furthermore, the username handling vulnerability might be abused to execute SQL statements on the phpBB database.

Workaround

There is a one-line patch which will remediate the remote execution vulnerability.

Locate the following block of code in viewtopic.php:

    //
    // Was a highlight request part of the URI?
    //
    $highlight_match = $highlight = '';
    if (isset($HTTP_GET_VARS['highlight']))
    {
       // Split words and phrases
       $words = explode(' ', trim(htmlspecialchars(urldecode($HTTP_GET_VARS['highlight']))));
    
       for($i = 0; $i < sizeof($words); $i++)
       {

Replace with the following:


    //
    // Was a highlight request part of the URI?
    //
    $highlight_match = $highlight = '';
    if (isset($HTTP_GET_VARS['highlight']))
    {
       // Split words and phrases
       $words = explode(' ', trim(htmlspecialchars($HTTP_GET_VARS['highlight'])));
    
       for($i = 0; $i < sizeof($words); $i++)
       {

Resolution

All phpBB users should upgrade to the latest version to fix all known vulnerabilities:

    # emerge --sync
    # emerge --ask --oneshot --verbose ">=www-apps/phpbb-2.0.11"

References

Availability

This GLSA and any updates to it are available for viewing at the Gentoo Security Website: http://security.gentoo.org/glsa/glsa-200411-32.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@gentoo.org or alternatively, you may file a bug at https://bugs.gentoo.org.