The WHM interface 11.15.0 for cPanel 11.18 before 11.18.4 and 11.22 before 11.22.3 allows remote attackers to bypass XSS protection and inject arbitrary script or HTML via repeated, improperly-ordered "<" and ">" characters in the (1) issue parameter to scripts2/knowlegebase, (2) user parameter to scripts2/changeip, (3) search parameter to scripts2/listaccts, and other unspecified vectors.