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.
2019-07-02T21:15:10.493
2024-11-21T03:33:59.780
Modified
CVSSv3.1: 9.8 (CRITICAL)
AV:N/AC:L/Au:N/C:C/I:C/A:C
10.0
10.0
| Type | Vendor | Product | Version/Range | Vulnerable? |
|---|---|---|---|---|
| Operating System | dlink | dcs-1130_firmware | - | Yes |
| Hardware | dlink | dcs-1130 | - | No |
| Operating System | dlink | dcs-1100_firmware | - | Yes |
| Hardware | dlink | dcs-1100 | - | No |