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MEDIUM severity

CVE-2009-0783 tomcat

MEDIUM

CVE-2009-0783 is a medium-severity (CVSS 4.2) Information Exposure vulnerability in org.apache.tomcat:tomcat. A fix is available for org.apache.tomcat:tomcat — see the affected versions and patch details below.

Exposure of Sensitive Information to an Unauthorized Actor in Apache Tomcat

Published
May 2, 2022
Updated
Apr 9, 2025
Affected
3 pkgs
Patched
1 / 3
Exploits
None indexed
Exploitation data as of Sep 19, 2026 · OSV.dev, NVD, FIRST.org (EPSS)

EPSS Exploitation Probability

via FIRST.org ↗
0.8%probability of exploitation in next 30 days
Lower Risk0.00%
Lower risk than most CVEs55th percentile — riskier than 55% of all scored CVEsHighest risk

EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.

How urgent is this, really

CVE-2009-0783 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.

Where this sits among everything scored

Of 377,238 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.

Real-World Exposure

3 pkgs affected
org.apache.tomcat:tomcatorg.apache.tomcat:tomcatorg.apache.tomcat:tomcat

Real-time download stats are indexed for npm and PyPI packages. This vulnerability affects Maven packages — download data is not available via public APIs for these ecosystems.

Description

Apache Tomcat 4.1.0 through 4.1.39, 5.5.0 through 5.5.27, and 6.0.0 through 6.0.18 permits web applications to replace an XML parser used for other web applications, which allows local users to read or modify the (1) web.xml, (2) context.xml, or (3) tld files of arbitrary web applications via a crafted application that is loaded earlier than the target application.

Affected Packages

3 total 1 fixed
EcosystemPackageVulnerable rangeFix
Mavenorg.apache.tomcat:tomcat4.1.0No fix
Mavenorg.apache.tomcat:tomcat5.5.0No fix
Mavenorg.apache.tomcat:tomcat6.0.0&&< 6.0.206.0.20org.apache.tomcat:tomcat:6.0.20

Detection & mitigation playbook

Open-source dependency
  1. Detect

    Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for org.apache.tomcat:tomcat, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.

  2. Fix

    No patched version of org.apache.tomcat:tomcat has shipped for CVE-2009-0783 yet. Where your build allows, override or pin the dependency away from the vulnerable range, and apply any maintainer-recommended mitigation.

  3. Workarounds

    If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.

  4. How O3 protects you

    O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2009-0783 can be triaged on real exposure rather than presence alone.

Tailored to CVE-2009-0783. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.

Fixing This On Your OS

If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.

Red HatLow
ProductFixed inAdvisory
JBEAP 4.2.0 for RHEL 4hibernate3-1:3.2.4-1.SP1_CP08.0jpp.ep1.2.el4RHSA-2009:1144
JBEAP 4.2.0 for RHEL 5hibernate3-1:3.2.4-1.SP1_CP08.0jpp.ep1.2.3.el5RHSA-2009:1143
JBEWS 1.0 for RHEL 4tomcat5-0:5.5.23-1.patch07.19.ep5.el4RHSA-2009:1454
JBEWS 1.0 for RHEL 4tomcat6-0:6.0.18-11.3.ep5.el4RHSA-2009:1506
Red Hat Developer Suite V.3tomcat5-0:5.5.23-0jpp_18rhRHSA-2009:1563
Red Hat Enterprise Linux 5tomcat5-0:5.5.23-0jpp.7.el5_3.2RHSA-2009:1164
Red Hat JBoss Enterprise Application Platform 4.3 for RHEL 4glassfish-jaxb-0:2.1.4-1.11.ep1.el4RHSA-2009:1146
Red Hat JBoss Enterprise Application Platform 4.3 for RHEL 5glassfish-jaxb-0:2.1.4-1.11.1.ep1.el5RHSA-2009:1145
UbuntuMEDIUM

Frequently Asked Questions

Apache Tomcat 4.1.0 through 4.1.39, 5.5.0 through 5.5.27, and 6.0.0 through 6.0.18 permits web applications to replace an XML parser used for other web applications, which allows local users to read or modify the (1) web.xml, (2) context.xml, or (3) tld files of arbitrary web applications via a crafted application that is loaded earlier than the target application.
O3 Security · Impact-Aware SCA

Is CVE-2009-0783 in your dependencies?

O3 Security finds CVE-2009-0783 across Maven dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.

CVE-2009-0783: tomcat (Medium 4.2) | O3 Security