The policy definition evaluator in Condor before 7.4.2 does not properly handle attributes in a WANT_SUSPEND policy that evaluate to an UNDEFINED state, which allows remote authenticated users to cause a denial of service (condor_startd exit) via a crafted job.
https://htcondor-wiki.cs.wisc.edu/index.cgi/tktview?tn=1001
https://bugzilla.redhat.com/show_bug.cgi?id=540545
http://rhn.redhat.com/errata/RHSA-2010-0773.html
http://research.cs.wisc.edu/htcondor/manual/v7.6/8_5Stable_Release.html