Ceragon FibeAir IP-10 wireless radios contain a hidden user account with a default password set by the vendor. This user can be accessed via both the web interface and SSH. In the web interface, this simply grants an attacker read-only access to the device’s settings. However, when using SSH, this user gives an attacker access to a Linux shell.
While the mateidu user does not have root privileges in the Linux shell, these devices run an outdated Linux kernel that may be vulnerable to privilege escalation exploits.
The vendor recommends that users “log as mateidu user and change the password via the GUI this will close the old internal protection port access. [sic]”
The mateidu user’s password is the same as its username.
This vulnerability is similar to CVE-2015-0936, which detailed the discovery of an RSA key pair that allowed an attacker to log in as the mateidu user via SSH.
Timeline:
- 2017/05/12 - Contacted vendor
- 2017/05/14 - Vendor acknowledges report
- 2017/05/16 - Vendor sends their recommendation
- 2017/05/18 - Publicly disclosed