Cross-site request forgery (CSRF) vulnerability in goform/usermanage in Grandstream GXV3501, GXV3504, GXV3601, GXV3601HD/LL, GXV3611HD/LL, GXV3615W/P, GXV3651FHD, GXV3662HD, GXV3615WP_HD, GXV3500, and possibly other camera models allows remote attackers to hijack the authentication of unspecified victims for requests that add users.