Auth bypass in Fermax Outdoor Panel

CVE-2017-16778

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).

Vulnerability class: Broken Access Control

EPSS: 0.006 (43.0th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 4.6 (Medium). Vector: CVSS:3.1/AV:P/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N.

Affected products

Weakness classification (CWE)

Public proof-of-concept exploits

References

Frequently asked questions

What is CVE-2017-16778?
CVE-2017-16778 is a medium-severity vulnerability in Fermax Outdoor Panel, classified under Incorrect Authorization. CVSS score: 4.6/10. Published 2019-12-24.
How severe is CVE-2017-16778?
Medium severity. CVSS v3 base score is 4.6 out of 10.
Is CVE-2017-16778 known to be exploited?
1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.