CVE-2020-5206

Authentication Bypass For Endpoints With Anonymous Access in Opencast

Workarounds

As a workaround for older, unpatched versions, disabling remember-me cookies in etc/security/mh_default_org.xml will mitigate the problem but will obviously also disable this feature without obvious indication. To deactivate this, remove the following line from the security configuration:

<sec:remember-me … />

References

• Remember-me cookie in the security configuration file

For more information

If you have any questions or comments about this advisory:

• Open an issue in opencast/opencast
• For security-relevant information, email us at [email protected]

Using a remember-me cookie with an arbitrary username can cause Opencast to assume proper authentication for that user even if the remember-me cookie was incorrect given that the attacked endpoint also allows anonymous access.

This way, an attacker can, for example, fake a remember-me token, assume the identity of the global system administrator and request non-public content from the search service without ever providing any proper authentication.

CVE-2020-5206 has a CVSS score of 8.7 (Critical). The vector is network-reachable, low 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 (7.6, 8.1); upgrading removes the vulnerable code path.

Kodem intelligence

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This problem is fixed in Opencast 7.6 and Opencast 8.1

1. What is CVE-2020-5206? CVE-2020-5206 is a critical-severity security vulnerability in org.opencastproject:opencast-kernel (maven), affecting versions < 7.6. It is fixed in 7.6, 8.1.
2. How severe is CVE-2020-5206? CVE-2020-5206 has a CVSS score of 8.7 (Critical). 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-kernel are affected by CVE-2020-5206? org.opencastproject:opencast-kernel (maven) versions < 7.6 is affected.
4. Is there a fix for CVE-2020-5206? Yes. CVE-2020-5206 is fixed in 7.6, 8.1. Upgrade to this version or later.
5. Is CVE-2020-5206 exploitable, and should I be worried? Whether CVE-2020-5206 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-2020-5206 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-2020-5206?
   • Upgrade org.opencastproject:opencast-kernel to 7.6 or later
   • Upgrade org.opencastproject:opencast-kernel to 8.1 or later

Other vulnerabilities in org.opencastproject:opencast-kernel