CVE-2019-12406

Potential DOS attack due to unrestricted attachment count in messages

Apache CXF before 3.3.4 and 3.2.11 does not restrict the number of message attachments present in a given message. This leaves open the possibility of a denial of service type attack, where a malicious user crafts a message containing a very large number of message attachments. From the 3.3.4 and 3.2.11 releases, a default limit of 50 message attachments is enforced. This is configurable via the message property "attachment-max-count".

The application allocates resources such as memory, threads, or file descriptors based on untrusted input without enforcing a cap. Typical impact: resource exhaustion leading to denial of service.

CVE-2019-12406 has a CVSS score of 6.5 (Medium). The vector is network-reachable, no privileges required, and user interaction required. 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 (3.2.11, 3.3.4); upgrading removes the vulnerable code path.

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1. What is CVE-2019-12406? CVE-2019-12406 is a medium-severity allocation of resources without limits or throttling vulnerability in org.apache.cxf:cxf (maven), affecting versions < 3.2.11. It is fixed in 3.2.11, 3.3.4. The application allocates resources such as memory, threads, or file descriptors based on untrusted input without enforcing a cap.
2. How severe is CVE-2019-12406? CVE-2019-12406 has a CVSS score of 6.5 (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.
3. Which packages are affected by CVE-2019-12406?
   • org.apache.cxf:cxf (maven) (versions < 3.2.11)
   • org.apache.cxf:apache-cxf (maven) (versions < 3.2.11)
4. Is there a fix for CVE-2019-12406? Yes. CVE-2019-12406 is fixed in 3.2.11, 3.3.4. Upgrade to this version or later.
5. Is CVE-2019-12406 exploitable, and should I be worried? Whether CVE-2019-12406 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
6. What actually determines whether CVE-2019-12406 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.
7. How do I fix CVE-2019-12406?
   • Upgrade org.apache.cxf:cxf to 3.2.11 or later
   • Upgrade org.apache.cxf:cxf to 3.3.4 or later
   • Upgrade org.apache.cxf:apache-cxf to 3.2.11 or later
   • Upgrade org.apache.cxf:apache-cxf to 3.3.4 or later

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