Authentication Bypass For Endpoints With Anonymous Access in OpencastCVE-2020-5206

### 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 [email protected]

Quoted source text, attributed separately from HOL analysis.