PT-2019-8638 · D Link+1 · D-Link Dcs-1130+2

Mandar Satam · Published 2019-07-02 · Updated 2021-04-26 · CVE-2017-8415

Positive Technologies (AI Summary)

CVSS v2.0

10

High

Base vector

AV:N/AC:L/Au:N/C:C/I:C/A:C

Name of the Vulnerable Software and Affected Versions D-Link DCS-1100 (affected versions not specified) D-Link DCS-1130 (affected versions not specified)

Description An issue was discovered on D-Link devices, where a custom telnet daemon as part of the busybox retrieves the password from the shadow file using the getspnam function. It then performs a crypt operation on the password retrieved from the user and checks if the password is correct or incorrect using strcmp. However, the /etc/shadow file is part of a CRAM-FS filesystem, which means the user cannot change the password. A hardcoded hash in /etc/shadow is used to match the credentials provided by the user, which is a salted hash of the string "admin" and acts as a password to the device.

Recommendations For D-Link DCS-1100, consider disabling the telnet daemon until a patch is available. For D-Link DCS-1130, consider disabling the telnet daemon until a patch is available. At the moment, there is no information about a newer version that contains a fix for this vulnerability.

Using Hardcoded Credentials

Weakness Enumeration

CWE-798

Related Identifiers

CVE-2017-8415

Affected Products

Busybox

D-Link Dcs-1100

D-Link Dcs-1130

References · 5

• https://nvd.nist.gov/vuln/detail/CVE-2017-8415 · Security Note
• https://github.com/ethanhunnt/IoT_vulnerabilities/blob/master/Dlink_DCS_1130_security.pdf · Note
• https://t.me/cibsecurity/5308 · Telegram Post
• http://packetstormsecurity.com/files/153226/Dlink-DCS-1130-Command-Injection-CSRF-Stack-Overflow.html · Note
• https://seclists.org/bugtraq/2019/Jun/8 · Note