netVigilance Security Advisory #10 dt_guestbook version 1.0f XSS vulnerability Description: dt_guestbook is a fully-featured message board system with admin interface. Due to program flaws it is possible for the remote attacker to conduct XSS attacks. The remote attacker can convince the victim to open a specially crafted link that is a trusted guestbook server and execute arbitrary code in the user’s browser session. External References: Mitre CVE: CVE-2006-6487 http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2006-6487 NVD NIST: CVE-2006-6487 http://nvd.nist.gov/nvd.cfm?cvename=CVE-2006-6487 OSVDB: 30787 http://www.osvdb.com/displayvuln.php?osvdb_id=30787 Summary: dt_guestbook a fully-featured message board system with admin interface. A security problem in the product allows attackers to conduct XSS attacks. This vulnerability can be exploited only when PHP register_globals is On. Release Date: Severity: Risk: Medium CVSS Metrics Access Vector: Remote Access Complexity: High Authentication: not-required Confidentiality Impact: Partial Integrity Impact: Partial Availability Impact: Partial Impact Bias: Normal CVSS Base Score: 5.6 Target Distribution on Internet: Low Exploitability: Functional Exploit Remediation Level: Workaround Report Confidence: Uncorroborated Vulnerability Impact: Attack Host Impact: cross-site scripting. SecureScout Testcase ID: TC 17940 Vulnerable Systems: dt_guestbook 1.0f. Vulnerability Type: XSS (Cross-Site Scripting) to force a web-site to display malicious contents to the target, by sending a specially crafted request to the web-site. The vulnerable web-site is not the target of attack but is used as a tool for the hacker in the attack of the victim. Vendor Status: Author Alexander Fedorov was notified on Dec 8 2006 and agreed to correct the XSS in his product. He has failed to respond to emails or Chat since Dec 8 2006. . Solution: Patch Possibly Pending from Vendor, please check http://fedorov.vitalain.ru for updates. . Workaround: Set PHP register_globals to Off. Example: HTTP REQUEST http://[TARGET]/[dt_guestbook_v1-directory]/index.php?submit=1&error[]=%3Cscript%3Ealert(document.cookie)%3C/script%3E REPLY ... will execute ... Advisory URL: http://www.netvigilance.com/advisory0009 Credits: Jesper Jurcenoks Co-founder netVigilance, Inc www.netvigilance.com