Quantum Secular Labs / Blog / Advisories

CVE-2018-19524: Skyworthdigital Dt740 Firmware: Authentication bypass

CVE-2018-19524 is rated critical with a CVSS v3.0 base score of 9.8 and NVD lists 3 affected products, including Skyworthdigital Dt740 Firmware. Per its scoring, it can be exploited over the network, without authentication, without any user interaction. The scored impact on confidentiality, integrity and availability is the highest available.

Vulnerability description

An issue was discovered on Shenzhen Skyworth DT741 Converged Intelligent Terminal (G/EPON+IPTV) SDOTBGN1, DT721-cb SDOTBGN1, and DT741-cb SDOTBGN1 devices. A long password to the Web_passwd function allows remote attackers to cause a denial of service (segmentation fault) or achieve unauthenticated remote code execution because of control of registers S0 through S4 and T4 through T7.

Severity breakdown

CVSS v3.0 9.8: CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Attack vector: Network. Exploitable remotely over the network, with no need for local or physical access.
Attack complexity: Low. No special conditions; the attack can be repeated reliably.
Privileges required: None. No account or prior access is needed.
User interaction: None. No action from any user is needed.
Scope: Unchanged. Impact stays within the vulnerable component.
Confidentiality impact: High. Total loss of confidentiality; sensitive data can be fully disclosed.
Integrity impact: High. Total loss of integrity; data or system state can be fully modified.
Availability impact: High. Total loss of availability; the component can be shut down.

Underlying weakness

CWE-20: Improper Input Validation

The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.

Affected products

Skyworthdigital Dt740 Firmware: sdotbgn1
Skyworthdigital Dt721 Cb Firmware: sdotbgn1
Skyworthdigital Dt741 Cb Firmware: sdotbgn1