TBK DVR4104 and DVR4216 devices, as well as Novo, CeNova, QSee, Pulnix, XVR 5 in 1, Securus, Night OWL, DVR Login, HVR Login, and MDVR Login, which run re-branded versions of the original TBK DVR4104 and DVR4216 series, allow remote attackers to bypass authentication via a "Cookie: uid=admin" header, as demonstrated by a device.rsp?opt=user&cmd=list request that provides credentials within JSON data in a response.