Summary
XML external entity (XXE) processing ('external-parameter-entities' feature was not fully disabled))
Due to an incomplete fix for CVE-2019-9658, checkstyle was still vulnerable to XML External Entity (XXE) Processing.
User: Build Maintainers
This vulnerability probably doesn't impact Maven/Gradle users as, in most cases, these builds are processing files that are trusted, or pre-vetted by a pull request reviewer before being run on internal CI infrastructure.
User: Static Analysis as a Service
If you operate a site/service that parses "untrusted" Checkstyle XML configuration files, you are vulnerable to this and should patch.
Note from the discoverer of the original CVE-2019-9658:
While looking at a few companies that run Checkstyle/PMD/ect... as a service I notice that it's a common pattern to run the static code analysis tool inside of a Docker container with the following flags:
--net=none \
--privileged=false \
--cap-drop=ALL
Running the analysis in Docker has the advantage that there should be no sensitive local file information that XXE can exfiltrate from the container. Additionally, these flags prevent vulnerabilities in static analysis tools like Checkstyle from being used to exfiltrate data via XXE or to perform SSRF.
- Jonathan Leitschuh
Workarounds
Is there a way for users to fix or remediate the vulnerability without upgrading?
No workaround are available
References
- CWE-611: Improper Restriction of XML External Entity Reference
- GitHub Issue https://github.com/checkstyle/checkstyle/issues/7468
For more information
If you have any questions or comments about this advisory:
- Open an issue in https://github.com/checkstyle/checkstyle/issues
Impact
An XML parser processes external entity references in untrusted input, causing the server to fetch internal resources or remote URLs. Typical impact: local file disclosure, server-side request forgery, or denial of service.
CVE-2019-10782 has a CVSS score of 5.3 (Medium). The vector is network-reachable, no privileges required, and no user interaction. A CVSS score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether this affects your application depends on whether the vulnerable code is present and reachable in your environment. A fixed version is available (8.29); upgrading removes the vulnerable code path.
Affected versions
Security releases
Kodem intelligence
Severity tells you how bad this could be in the worst case. It does not tell you whether you are exposed. Exploitability and impact are functions of runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A vulnerable package can sit in your dependency tree and never run.
Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter. Kodem's runtime-powered SCA identifies whether this CVE is reachable in your applications.
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Has the problem been patched? What versions should users upgrade to?
Patched, will be released with version 8.29 at 26 Jan 2020.
Frequently Asked Questions
- What is CVE-2019-10782? CVE-2019-10782 is a medium-severity XML external entity injection (XXE) vulnerability in com.puppycrawl.tools:checkstyle (maven), affecting versions < 8.29. It is fixed in 8.29. An XML parser processes external entity references in untrusted input, causing the server to fetch internal resources or remote URLs.
- How severe is CVE-2019-10782? CVE-2019-10782 has a CVSS score of 5.3 (Medium). This score reflects the worst-case severity of the vulnerability, not your specific exposure. Whether it represents real risk in your environment depends on whether the vulnerable code is present and reachable.
- Which versions of com.puppycrawl.tools:checkstyle are affected by CVE-2019-10782? com.puppycrawl.tools:checkstyle (maven) versions < 8.29 is affected.
- Is there a fix for CVE-2019-10782? Yes. CVE-2019-10782 is fixed in 8.29. Upgrade to this version or later.
- Is CVE-2019-10782 exploitable, and should I be worried? Whether CVE-2019-10782 is exploitable in your environment depends on whether the vulnerable code is present and reachable. A CVSS score is a worst-case rating; it does not account for your specific deployment, configuration, or usage patterns. Kodem, an Intelligent Application Security platform, uses runtime intelligence to show which vulnerabilities actually execute in production, so you can focus on the ones that represent real risk. Get a demo
- What actually determines whether CVE-2019-10782 is exploitable, and how bad it is? Exploitability and impact are not fixed properties of a CVE. They depend on runtime truth: whether the vulnerable code is present, reachable, and actually executes in your application. A high CVSS score on a dependency that never runs is not the same as real risk. Kodem, an Intelligent Application Security platform, uses runtime intelligence to reveal which vulnerabilities actually execute in production, so teams prioritize the ones that genuinely matter.
- How do I fix CVE-2019-10782? Upgrade
com.puppycrawl.tools:checkstyleto 8.29 or later.