TomcatWeb server / proxy · Apache
CVE-2002-0493
Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.
NVD · uneditedApache Tomcat may be started without proper security settings if errors are encountered while reading the web.xml file, which could allow attackers to bypass intended restrictions.
Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.
dbcve analysis · moderate confidenceWhen Apache Tomcat encounters errors while parsing the web.xml deployment descriptor, it may start the application without applying the security constraints defined in that file, allowing attackers to bypass intended access restrictions.
Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.
Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.
NVD · CPE data
TomcatWeb server / proxy
<= 3.3.2CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.
From the vector- Attack vector
- Network
- Complexity
- Low
- Authentication
- None
- Confidentiality
- Partial
- Integrity
- Partial
- Availability
- Partial
AV:N/AC:L/Au:N/C:P/I:P/A:P
Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.
dbcve checksWork through these to decide whether this CVE applies to you.
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Identify the installed Tomcat versionCheck the version banner displayed when Tomcat starts, or examine the RELEASE-NOTE or VERSION files in the Tomcat installation directory. Common locations: $CATALINA_HOME/RELEASE-NOTES or the servlet.jar manifest.Affected if The version is 3.3.2 or lower (any 3.x release up to and including 3.3.2)
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Locate the web.xml deployment descriptorFind the web.xml file in the WEB-INF directory of the affected web application. Typical path: $CATALINA_HOME/webapps/<appname>/WEB-INF/web.xmlAffected if A web.xml file exists and contains <security-constraint> elements
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Validate web.xml for parsing errorsUse an XML parser to validate the web.xml file syntax. Run: xmllint --noout /path/to/web.xml or manually attempt to parse it with any XML tool.Affected if The web.xml file contains XML syntax errors or malformed elements that would cause parsing to fail
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Determine if Tomcat started despite web.xml errorsReview Tomcat startup logs for warnings or errors related to web.xml parsing. Check for messages indicating failed constraint loading or configuration warnings during application startup.Affected if Tomcat started and the application is running, but the logs show web.xml parsing failures or warnings
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Verify security constraints are actually enforcedAttempt to access URLs protected by security constraints in web.xml using an unauthenticated or unauthorized request. Compare the actual access behavior against what the security constraint specifies.Affected if Access is granted to resources that should be restricted by security constraints, indicating constraints were not applied
You are affected if running Tomcat 3.3.2 or earlier and your web.xml has parsing errors that caused security constraints to be ignored during startup.
Generated from the published advisory. Verify against your own configuration.
Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.
From vendor dataValidate the web.xml file for syntax errors before deployment, ensure Tomcat starts only after successful configuration loading, and consider upgrading to a patched Tomcat version if this is a known parsing bug in the deployed version.
Fix this in Tomcat
Scoped from the published advisory
- Consultation3.0 h
- Implementation4.0 h
- Testing2.0 h
- Review / QA2.0 h
An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $3,168.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2002-0493 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.
References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.
Primary sourcesPractitioner notes
ContributedPeer-ranked notes from engineers who’ve handled CVE-2002-0493 in production — separate from our analysis above.
The advisory tells you what broke. It rarely tells you what actually worked. If you’ve dealt with this one, that detail is what the next engineer is searching for.
- The version that genuinely resolved it — not the one the vendor claimed
- A config change or rule that shut the vector down
- A gotcha in the upgrade path that cost you an afternoon
No notes yet
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- Verified mitigations, workarounds, and config changes
- Version or environment caveats, and links to real fixes
- No weaponised exploit code, or anything meant to cause harm
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