CVE-2017-8415

moderate-risk
Published 2019-07-02

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.

Do I need to act?

~
3.1% chance of exploitation in next 30 days
EPSS score — moderate exploit probability
-
Not on CISA KEV list
No confirmed active exploitation reported to CISA
?
Patch status unknown
Check vendor advisories for fix availability and mitigation guidance
9
CVSS 9.8/10 Critical
NETWORK / LOW complexity

Affected Products (2)

Affected Vendors

Dlink

References (6)

Third Party Advisory http://packetstormsecurity.com/files/153226/Dlink-DCS-1130-Command-Injection-CSR...
Not Applicable https://github.com/ethanhunnt/IoT_vulnerabilities/blob/master/Dlink_DCS_1130_sec...
Mailing List https://seclists.org/bugtraq/2019/Jun/8
Third Party Advisory http://packetstormsecurity.com/files/153226/Dlink-DCS-1130-Command-Injection-CSR...
Not Applicable https://github.com/ethanhunnt/IoT_vulnerabilities/blob/master/Dlink_DCS_1130_sec...
Mailing List https://seclists.org/bugtraq/2019/Jun/8
45
/ 100
moderate-risk
Severity 32/34 · Critical
Exploitability 6/34 · Minimal
Exposure 7/34 · Low