Auth bypass in Blackmagicdesign Web Presenter 4k

CVE-2025-57432

Blackmagic Web Presenter version 3.3 exposes a Telnet service on port 9977 that accepts unauthenticated commands. This service allows remote attackers to manipulate stream settings, including changing video modes and possibly altering device functionality. No credentials or authentication mechanisms are required to interact with the Telnet interface.

Vulnerability class: Broken Authentication

EPSS: 0.006 (45.3th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 9.8 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2025-57432?
CVE-2025-57432 is a critical-severity vulnerability in Blackmagicdesign Web Presenter 4k, classified under Missing Authentication for Critical Function. CVSS score: 9.8/10. Published 2025-09-22.
How severe is CVE-2025-57432?
Critical severity. CVSS v3 base score is 9.8 out of 10.