Cyber Posture

CVE-2025-50399

CriticalPublic PoC

Published: 26 November 2025

Published
26 November 2025
Modified
02 January 2026
KEV Added
Patch
CVSS Score 9.8 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.0007 21.6th percentile
Risk Priority 20 60% EPSS · 20% KEV · 20% CVSS

Description

Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.

Security Summary

CVE-2025-50399, published on 2025-11-26, is a buffer overflow vulnerability (CWE-120) affecting the FAST FAC1200R F400_FAC1200R_Q firmware or component. The issue resides in the function sub_80435780, which can be triggered via the password parameter. It has a CVSS v3.1 base score of 9.8, indicating critical severity due to its network accessibility, low attack complexity, lack of required privileges or user interaction, and high impacts on confidentiality, integrity, and availability.

An unauthenticated attacker with network access to the affected device can exploit this vulnerability remotely with low complexity and no user interaction. Successful exploitation could allow arbitrary code execution, potentially leading to full system compromise, data exfiltration, modification of device configurations, or denial of service.

References for this vulnerability are hosted on GitHub at https://github.com/sezangel/IOT-vul/tree/main/FAST/FAC1200R/1, which likely contain proof-of-concept details or analysis, though no official vendor advisories or patches are detailed in the available information.

Details

CWE(s)
CWE-120

Affected Products

fastcom
fac1200r firmware
f400_fac1200r_q

MITRE ATT&CK Enterprise Techniques

T1190 Exploit Public-Facing Application Initial Access
Adversaries may attempt to exploit a weakness in an Internet-facing host or system to initially access a network.
Why these techniques?

Buffer overflow in network-accessible firmware allows unauthenticated remote code execution on a public-facing application.

Confidence: HIGH · MITRE ATT&CK Enterprise v19.0

References