Insufficient cross site scripting protection in J-Web component in Juniper Networks Junos OS may potentially allow a remote unauthenticated user to inject web script or HTML and steal sensitive data and credentials from a J-Web session and to perform administrative actions on the Junos device. Juniper SIRT is not aware of any malicious exploitation of this vulnerability. Affected releases are Juniper Networks Junos OS 11.4 prior to 11.4R13-S3; 12.1X44 prior to 12.1X44-D60; 12.1X46 prior to 12.1X46-D40; 12.1X47 prior to 12.1X47-D30; 12.3 prior to 12.3R11; 12.3X48 prior to 12.3X48-D20; 13.2X51 prior to 13.2X51-D39, 13.2X51-D40; 13.3 prior to 13.3R9; 14.1 prior to 14.1R6; 14.2 prior to 14.2R6; 15.1 prior to 15.1R3; 15.1X49 prior to 15.1X49-D20; 15.1X53 prior to 15.1X53-D57.