In Opencast before 7.6 and 8.1, 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. This problem is fixed in Opencast 7.6 and Opencast 8.1

Affected: Maven: org.opencastproject:opencast-kernel

### Impact

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.

### Patches

This problem is fixed in Opencast 7.6 and Opencast 8.1

### 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:

```xml <sec:remember-me … /> ```

### References

- [Remember-me cookie in the security configuration file](https://github.com/opencast/opencast/blob/161ee619382f144dc35eea211fc6b556025b98e1/etc/security/mh_default_org.xml#L335-L336)

### For more information

If you have any questions or comments about this advisory:

- Open an issue in [opencast/opencast](https://github.com/opencast/opencast/issues) - For security-relevant information, email us at security@opencast.org