CVE-2017-8415 Information

Description

An issue was discovered on D-Link DCS-1100 and DCS-1130 devices. The device has a custom telnet daemon as a part of the busybox and retrieves the password from the shadow file using the function getspnam at address 0x00053894. Then performs a crypt operation on the password retrieved from the user at address 0x000538E0 and performs a strcmp at address 0x00053908 to check if the password is correct or incorrect. However the /etc/shadow file is a part of CRAM-FS filesystem which means that the user cannot change the password and hence a hardcoded hash in /etc/shadow is used to match the credentials provided by the user. This is a salted hash of the string \admin\ and hence it acts as a password to the device which cannot be changed as the whole filesystem is read only.

CVSS Vector

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

Reference

http://packetstormsecurity.com/files/153226/Dlink-DCS-1130-Command-Injection-CSRF-Stack-Overflow.html https://github.com/ethanhunnt/IoT_vulnerabilities/blob/master/Dlink_DCS_1130_security.pdf https://seclists.org/bugtraq/2019/Jun/8

Attack Complexity

LOW

Privileges Required

NONE

User Interaction Required

NONE

Scope

NONE

Confidentiality Impact

UNCHANGED

Integrity Impact

HIGH

Availability Impact

HIGH

Base Score

HIGH

Base Severity

9.8