CVE-2009-3421

Name: CVE-2009-3421
Creator: NVD / NIST
Published: 2009-09-25T22:30:16.03+00:00
License: https://creativecommons.org/publicdomain/zero/1.0/

CRITICALCVSS 9.8/10EPSS 4.99%

Last modified Jun 16, 2026

CVE-2009-3421 is a critical-severity vulnerability rated 9.8/10 on the CVSS scale. login.php in Zenas PaoBacheca Guestbook 2.1, when register_globals is enabled, allows remote attackers to bypass authentication and gain administrative access by setting the login_ok parameter to 1.. EPSS estimates a 4.99% chance of exploitation in the next 30 days.

Description

login.php in Zenas PaoBacheca Guestbook 2.1, when register_globals is enabled, allows remote attackers to bypass authentication and gain administrative access by setting the login_ok parameter to 1.

Metrics

CVSS 3.1

9.8/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS Probability

4.99%

91.1th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-287

Affected Software

Vendor	Product	Versions
Zenas	Pao-Bacheca Guestbook	2.1

References

http://secunia.com/advisories/36023Broken Link, Vendor Advisory
http://www.exploit-db.com/exploits/9293Third Party Advisory, VDB Entry
http://www.osvdb.org/56757Broken Link, Exploit
https://exchange.xforce.ibmcloud.com/vulnerabilities/52100Third Party Advisory, VDB Entry
http://secunia.com/advisories/36023Broken Link, Vendor Advisory
http://www.exploit-db.com/exploits/9293Third Party Advisory, VDB Entry
http://www.osvdb.org/56757Broken Link, Exploit
https://exchange.xforce.ibmcloud.com/vulnerabilities/52100Third Party Advisory, VDB Entry

Timeline

Published: Sep 25, 2009
Last Modified: Jun 16, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2009-3421?

login.php in Zenas PaoBacheca Guestbook 2.1, when register_globals is enabled, allows remote attackers to bypass authentication and gain administrative access by setting the login_ok parameter to 1.

How severe is CVE-2009-3421?

CVE-2009-3421 has a CVSS score of 9.8/10 (CRITICAL severity). The EPSS model estimates a 4.99% probability of exploitation in the next 30 days.

How do I fix CVE-2009-3421?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.

Are you affected by CVE-2009-3421?

Run a free Strix scan to check your systems for this vulnerability.

Scan your code now

Source: NVD / NIST