Original Release Date: 2013-09-13 | Last Revised: 2013-12-04
Overview
Digital video recorders (DVR) produced by Dahua Technology Co., Ltd. contain multiple vulnerabilities that could allow a remote attacker to gain privileged access to the devices.
CWE-798: Use of Hard-coded Credentials - CVE-2013-3612 All DVRs of the same series ship with the same default root password on a read-only partition. Therefore, the root password can only be changed by flashing the firmware. Additionally, a separate hard-coded remote backdoor account exists that can be used to control cameras and other system components remotely. It is only accessible if authorization is done through ActiveX or the stand-alone client. Additionally, a hash of the current date can be used as a master password to gain access to the system and reset the administrator's password.
CWE-294: Authentication Bypass by Capture-reply - CVE-2013-3613 The DVR appliance accepts UPnP requests from external untrusted devices. This can cause the telnet port of a DVR appliance to be automatically forwarded and accessible by external parties. These default conditions could allow an external attacker to detect the device and authenticate using the hard-coded credentials.
CWE-521: Weak Password Requirements - CVE-2013-3614 The device enforces insufficient password requirements. User passwords are limited to only six characters in length, making them computationally feasible to discover using brute-force methods.
CWE-916: Use of Password Hash with Insufficient Computational Effort - CVE-2013-3615 User passwords are hashed with a weak 48-bit algorithm, and are therefore susceptible to brute-force attacks within a reasonable amount of time.
An unauthenticated remote attacker could gain privileged access to the device and compromise the confidentiality and integrity of its data. Additionally, the attacker could cause a denial-of-service.
Solution
We are currently unaware of a practical solution to this problem. Please consider the following workarounds.
Restrict Access
If possible, restrict access to the device using IP access lists and block UPnP requests from untrusted external devices.
Notified: July 09, 2013 Updated: December 04, 2013
Status
Unknown
Vendor Statement
Five separate attempts to contact Dahua were made, but the vendor failed to respond.
After publishing, Dahua disputes CVE-2013-3612, CVE-2013-3613, and CVE-2013-3614. Specifically, Dahua states that the telnet port cannot be mapped via UPnP. Dahua also states that the six character password requirement cannot be brute forced due to an account lockout mechanism after three unsuccessful login attempts. Lastly, Dahua states that the master password in CVE-2013-3612 can only be used by a local user.