IBM Rational ClearQuest 7.0.x before 7.0.1.11 7.1.1.x before 7.1.1.4 and 7.1.2.x before 7.1.2.1 does not prevent modification of back-reference fields which allows remote authenticated users to interfere with intended record relationships and possibly cause a denial of service (loop) or have unspecified other impact by (1) adding or (2) removing a back reference.