The addjob function in scheduler/ipp.c in cupsd in CUPS before 2.0.3 performs incorrect free operations for multiple-value job-originating-host-name attributes, which allows remote attackers to trigger data corruption for reference-counted strings via a crafted (1) IPPCREATEJOB or (2) IPPPRINT_JOB request, as demonstrated by replacing the configuration file and consequently executing arbitrary code.