RT is an open source, enterprise-grade issue and ticket tracking system. Versions prior to 5.0.10, 6.0.0 and above, prior to 6.0.3 contain an information disclosure and privilege escalation vulnerability in the REST 2.0 API. A privileged (non-administrative) user can obtain authentication credentials belonging to other users — including users with administrative privileges — and use those credentials to read data as those users via RT's feed endpoints. The same request that exposes the credentials also rotates them, invalidating previously-distributed feed URLs across the instance. This issue has been fixed in versions 5.0.10 and 6.0.3.