CVE-2003-0042 — tomcat
CVE-2003-0042 is a security vulnerability in org.apache.tomcat:tomcat. 1 public exploit reference exists, so weaponization risk is real. A fix is available for org.apache.tomcat:tomcat — see the affected versions and patch details below.
Jakarta Tomcat Directory Listing vulnerability
EPSS Exploitation Probability
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.
Real-World Exposure
org.apache.tomcat:tomcatReal-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
Jakarta Tomcat before 3.3.1a, when used with JDK 1.3.1 or earlier, allows remote attackers to list directories even with an index.html or other file present, or obtain unprocessed source code for a JSP file, via a URL containing a null character.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| ☕Maven | org.apache.tomcat:tomcat | all versions | 3.3.1aorg.apache.tomcat:tomcat:3.3.1a |
Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
Apache Tomcat 3.x - Null Byte Directory / File Disclosure
by Jouko Pynnönen · Jan 26, 2003
Detection & mitigation playbook
Open-source dependencyDetect
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.
Fix
Update org.apache.tomcat:tomcat to 3.3.1a or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2003-0042 is resolved across your whole dependency graph.
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.
How O3 protects you
O3 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2003-0042 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2003-0042. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2003-0042 in your dependencies?
O3 Security finds CVE-2003-0042 across Maven dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.