Condor before 7.8.2 allows remote attackers to bypass host-based authentication and execute actions such as ALLOW_ADMINISTRATOR or ALLOW_WRITE by connecting from a system with a spoofed reverse DNS hostname.
Condor 6.5.4 through 7.2.4, 7.3.x, and 7.4.0, as used in MRG, Grid for MRG, and Grid Execute Node for MRG, allows remote authenticated users to queue jobs as an arbitrary user, and thereby gain privileges, by using a Condor command-line tool to modify an unspecified job attribute.