An access control weakness in the DTMF tone receiver of Fermax Outdoor Panel allows physical attackers to inject a Dual-Tone-Multi-Frequency (DTMF) tone to invoke an access grant that would allow physical access to a restricted floor/level. By design, only a residential unit owner may allow such an access grant. However, due to incorrect access control, an attacker could inject it via the speaker unit to perform an access grant to gain unauthorized access, as demonstrated by a loud DTMF tone representing '1' and a long '#' (697 Hz and 1209 Hz, followed by 941 Hz and 1477 Hz).
CWE-863 - Incorrect Authorization
Authorization is a security mechanism performed by an application to grant or deny access to the requested resources by verifying the privileges of the user. When an application lacks effective authorization mechanisms, it enables unauthorized users to gain unintended privileges and illegitimate access to resources. Such a vulnerability may result in exposure of sensitive information, denial of service, arbitrary code execution, and complete system takeover.