ResteasyApplication · Redhat
CVE-2016-6347
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 · uneditedCross-site scripting (XSS) vulnerability in the default exception handler in RESTEasy allows remote attackers to inject arbitrary web script or HTML via unspecified vectors.
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 confidenceCross-site scripting (XSS) vulnerability in RESTEasy's default exception handler allows attackers to inject arbitrary HTML or script into web responses via unsanitized exception output. The default exception handler fails to properly encode or validate exception messages before rendering them in HTTP responses.
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
ResteasyApplication
all versionsCVSS 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
- Privileges
- None
- User interaction
- Required
- Scope
- Changed
- Confidentiality
- Low
- Integrity
- Low
- Availability
- None
CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N
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 RESTEasy dependencySearch your project's dependency files (pom.xml, build.gradle, package.json) and runtime classpath for resteasy-core, jboss resteasy, or org.jboss.resteasy librariesAffected if RESTEasy dependencies are present in the project
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Determine RESTEasy versionCheck the exact version of RESTEasy library in your dependency management (Maven, Gradle, or the JAR manifest files in /WEB-INF/lib)Affected if Any version of Red Hat RESTEasy is in use (the vulnerability affects all versions)
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Check for custom ExceptionMapperSearch source code for classes implementing javax.ws.rs.ext.ExceptionMapper interface, particularly ExceptionMapper<Exception> or ExceptionMapper<Throwable>Affected if No custom ExceptionMapper implementation exists - the application relies on RESTEasy's default exception handler
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Verify exception handling configurationReview web.xml and RESTEasy configuration files for <resteasy-servlet> or ResourceScanner setup, and check if custom exception providers are registered in Application classAffected if No custom exception provider is registered and the default RESTEasy servlet handles exceptions
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Test exception output encodingTrigger an unhandled exception in a REST endpoint (e.g., by causing a null pointer or runtime exception) and inspect the HTTP response body for raw exception message text that could contain script tagsAffected if Exception messages appear unencoded/escaped in the response (visible <, >, or script keywords without encoding)
Your environment is affected if Red Hat RESTEasy is in use AND no custom ExceptionMapper has been implemented to sanitize exception output before rendering.
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 dataConfigure RESTEasy to use a secure exception handler that properly encodes output, or implement custom exception mappers that sanitize all exception data before rendering. Input validation and output encoding should be applied to all user-controlled data in exception responses.
Fix this in Resteasy
Scoped from the published advisory
- Consultation4.0 h
- Implementation8.0 h
- Testing4.0 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 $5,120.
Scan for this in your stack
Free · runs locallyCheck whether your project pulls in CVE-2016-6347 — 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-2016-6347 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
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