Cyber Posture

CVE-2025-66045

CriticalPublic PoC

Published: 11 December 2025

Published
11 December 2025
Modified
17 December 2025
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 0.0019 40.7th percentile
Risk Priority 20 60% EPSS · 20% KEV · 20% CVSS

Description

Several stack-based buffer overflow vulnerabilities exists in the MFER parsing functionality of The Biosig Project libbiosig 3.9.1. A specially crafted MFER file can lead to arbitrary code execution. An attacker can provide a malicious file to trigger these vulnerabilities.When Tag…

more

is 65

Mitigating Controls (NIST 800-53 r5)AI

prevent

Directly remediates the stack-based buffer overflow flaws in libbiosig 3.9.1 MFER parsing by requiring timely patching or upgrading to a non-vulnerable version.

prevent

Mandates validation of MFER file inputs, including Tag 65 structures, to block specially crafted files from triggering buffer overflows.

prevent

Implements memory protection mechanisms like stack canaries and address space layout randomization to mitigate exploitation of stack-based buffer overflows in MFER parsing.

Security SummaryAI

CVE-2025-66045 involves several stack-based buffer overflow vulnerabilities (CWE-121 and CWE-787) in the MFER parsing functionality of The Biosig Project's libbiosig version 3.9.1. These flaws, specifically triggered when Tag is 65, can be exploited via a specially crafted MFER file, leading to arbitrary code execution.

The vulnerability carries a CVSS v3.1 base score of 9.8 (AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H), making it remotely exploitable over a network with low attack complexity, no required privileges, and no user interaction. Any attacker able to supply a malicious MFER file to a vulnerable application or system processing such files can achieve arbitrary code execution, resulting in high impacts to confidentiality, integrity, and availability.

Mitigation guidance is available in the Talos Intelligence advisory at https://talosintelligence.com/vulnerability_reports/TALOS-2025-2296.

Details

CWE(s)

Affected Products

libbiosig project
libbiosig
≤ 3.9.2

MITRE ATT&CK Enterprise TechniquesAI

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?

The vulnerability enables remote unauthenticated arbitrary code execution (AV:N/AC:L/PR:N/UI:N) via a specially crafted MFER file processed by vulnerable applications, directly facilitating T1190: Exploit Public-Facing Application.

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

References