CVE-2018-16153

The issue was mostly mitigated before, drastically reducing the risk. See references below for more information.

Workarounds

No workaround available.

References

• Patch fixing the issue
• Original security notice
• Original security mitigation

For more information

If you have any questions or comments about this advisory:

• Open an issue in our issue tracker
• Email us at [email protected]

Opencast before version 10.6 will try to authenticate against any external services listed in a media package when it is trying to access the files, sending the global system user's credentials, regardless of the target being part of the Opencast cluster or not.

Previous mitigations already prevented clear text authentications for such requests (e.g. HTTP Basic authentication), but with enough malicious intent, even hashed credentials can be broken.

CVE-2018-16153 has a CVSS score of 7.5 (High). 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 (10.6); upgrading removes the vulnerable code path.

Kodem intelligence

Opencast 10.6 will now send authentication requests only against servers which are part of the Opencast cluster, preventing external services from getting any form of authentication attempt in the first place.

1. What is CVE-2018-16153? CVE-2018-16153 is a high-severity security vulnerability in org.opencastproject:opencast-common (maven), affecting versions < 10.6. It is fixed in 10.6.
2. How severe is CVE-2018-16153? CVE-2018-16153 has a CVSS score of 7.5 (High). 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 versions of org.opencastproject:opencast-common are affected by CVE-2018-16153? org.opencastproject:opencast-common (maven) versions < 10.6 is affected.
4. Is there a fix for CVE-2018-16153? Yes. CVE-2018-16153 is fixed in 10.6. Upgrade to this version or later.
5. Is CVE-2018-16153 exploitable, and should I be worried? Whether CVE-2018-16153 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-2018-16153 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-2018-16153? Upgrade org.opencastproject:opencast-common to 10.6 or later.