Florian Weimer of the Red Hat Product Security Team found that an unauthenticated user able to connect to the Condor startd TCP port could request ads, provided they could guess or brute force the PID of the process, due to how the GIVE_REQUEST_AD handler is registered.  The ads contains a lot of already-public information for users with READ privileges, however it also provides the ClaimId (as opposed to the PublicClaimId which truncates the full value of the ClaimID).  If an attacker could obtain the private ClaimId, they could use it to control the running job, and also start new jobs on the system.