In the System → Maintenance tool, the Logged Users tab surfaces sessionId data for all users via the Direct Web Remoting API (UserSessionAjax.getSessionList.dwr) calls. While this is information that would and should be available to admins who possess "Sign In As" powers, admins who otherwise lack this privilege would still be able to utilize the session IDs to imitate other users.
While this is a very small attack vector that requires very high permissions to execute, its danger lies principally in obfuscating attribution; all Sign In As operations are attributed appropriately in the log files, and a malicious administrator could use this information to render their dealings untraceable — including those admins who have not been granted this ability — such as by using a session ID to generate an API token.
Fixed in: 24.07.12 / 23.01.20 LTS / 23.10.24v13 LTS / 24.04.24v5 LTS
References
In the System → Maintenance tool, the Logged Users tab surfaces sessionId data for all users via the Direct Web Remoting API (UserSessionAjax.getSessionList.dwr) calls. While this is information that would and should be available to admins who possess "Sign In As" powers, admins who otherwise lack this privilege would still be able to utilize the session IDs to imitate other users.
While this is a very small attack vector that requires very high permissions to execute, its danger lies principally in obfuscating attribution; all Sign In As operations are attributed appropriately in the log files, and a malicious administrator could use this information to render their dealings untraceable — including those admins who have not been granted this ability — such as by using a session ID to generate an API token.
Fixed in: 24.07.12 / 23.01.20 LTS / 23.10.24v13 LTS / 24.04.24v5 LTS
References