An issue in Grandstream UCM6510 v.1.0.20.52 and before allows a remote attacker to obtain sensitive information via the Login function at /cgi and /webrtccgi.

Grandstream Networks UCM6510 v1.0.20.52 and before is vulnerable to Improper Restriction of Excessive Authentication Attempts. An attacker can perform an arbitrary number of authentication attempts using different passwords and eventually gain access to the targeted account using a brute force attack.

The Grandstream UCM Series IP PBX before firmware version 1.0.20.52 is affected by a parameter injection vulnerability in the HTTP interface. A remote and authenticated attacker can execute arbitrary code by sending a crafted HTTP request. Authentication may be possible using a default user and password. Affected models are the UCM6202, UCM6204, UCM6208, and UCM6510.