CVE-2009-2901 Improper Authentication in Apache Tomcat

What is CVE-2009-2901?

CVE-2009-2901 is a medium-severity authentication bypass vulnerability in Apache Tomcat, published on 28 Jan 2010. An attacker can exploit it over the internet without logging in, with no action from the victim.

Official description

The autodeployment process in Apache Tomcat 5.5.0 through 5.5.28 and 6.0.0 through 6.0.20, when autoDeploy is enabled, deploys appBase files that remain from a failed undeploy, which might allow remote attackers to bypass intended authentication requirements via HTTP requests.

Weakness: CWE-264

Which versions are affected by CVE-2009-2901?

4 open source packages ship an affected version, including org.apache.tomcat:tomcat. It affects 1 product.

Products include Apache Tomcat.

How do I fix CVE-2009-2901?

Upgrade org.apache.tomcat:tomcat to a fixed version for your release line: 5.5.29 or 6.0.24.

Upgrade, and rotate credentials and sessions that may have been exposed. More about Authentication bypass.

Is CVE-2009-2901 being exploited?

There is no known exploitation of CVE-2009-2901 in the wild and no public exploit code.

Other vulnerabilities in Apache Tomcat

• CVE-2025-24813 Apache Tomcat Path Equivalence Exploited Critical 10.0
• CVE-2016-8735 Apache Tomcat Remote Code Execution Exploited Critical 9.8
• CVE-2017-12617 Apache Tomcat Remote Code Execution Exploited High 8.1
• CVE-2017-12615 Apache Tomcat on Windows Remote Code Execution Exploited High 8.1
• CVE-2026-34486 Apache Tomcat Missing Encryption of Sensitive Data Exploited High 7.5

All Apache Tomcat vulnerabilities

Sources

• CVE record
• NVD
• OSV
• GitHub advisory
• How this page is made

Also known as GHSA-hjfh-7c4v-7q8h.