Opencast is a free and open source solution for automated video capture and distribution at scale. Opencast versions prior to 11.7, users could pass along URLs for files belonging to organizations other than the user's own, which Opencast would then import into the current organization, bypassing organizational barriers. Attackers must have full access to Opencast's ingest REST interface, and also know internal links to resources in another organization of the same Opencast cluster. Users who do not run a multi-tenant cluster are not affected by this issue.
CWE-287 - Improper Authentication
Improper (or broken) authentication attacks are widespread, and have accounted for many of the worst data breaches in recent years. Improper authentication attacks are a class of vulnerabilities where an attacker impersonates a legitimate user by exploiting weaknesses in either session management or credential management to gain access to the user’s account. This can result in disclosure of sensitive information, and can lead to system compromise, theft, identity theft, and fraud.