A five-year-old authentication bypass vulnerability present in TBK DVR4104 and DVR4216 TBK Vision devices is being actively exploited in attacks. TBK DVR (digital video recording) devices are sold under other brand names including Novo, CeNova, QSee, Pulnix, XVR 5 in 1, Securus, Night OWL, DVR Login, HVR Login, and MDVR. The wide range of rebrands and the variety of sectors that these TBK DVR devices are supplied to mean these attacks could target individuals who are not even aware they are vulnerable. FortiGuard Labs, the threat research group from Fortinet, have published an Outbreak Alert about the attacks exploiting this unpatched vulnerability. Attackers are able to easily perform these attacks due to proof of concept (PoC) code for this exploit being publicly available on GitHub. 

The vulnerability exploited in these attacks is tracked as CVE-2018-9995. This critical severity flaw has a CVSS base score of 9.8, and has seemingly never had a patch issued for it by the vendor despite being first identified in May 2018. This vulnerability can be exploited by a remote attacker, who can send a specially crafted HTTP cookie to the vulnerable system. This allows them to use a Cookie: uid=admin header to bypass authentication and elevate to administrator level privileges. Once these privileges are obtained, the remote attackers have access to the camera video feeds of the vulnerable devices. FortiGuard Labs researchers have detected a recent spike in IPS detections, which is indicative of these attacks. 

As there is no vendor supplied patch for this flaw, and a range of rebrands have occurred causing the vulnerable systems to be distributed under a range of names, all users of DVR systems should review their devices to find out if they are vulnerable to this form of attack. The IPS signature can be configured to block attacks on vulnerable devices, however this is not a permanent fix. Vulnerable devices should be replaced as soon as possible with updated system to best prevent falling victim to these attacks.