CVE-2025-54481
Published: 25 August 2025
Summary
CVE-2025-54481 is a critical-severity Stack-based Buffer Overflow (CWE-121) vulnerability in Libbiosig Project Libbiosig. Its CVSS base score is 9.8 (Critical).
Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Client Execution (T1203); ranked in the top 44.1% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.
The strongest mitigations our analysis identified are NIST 800-53 SI-10 (Information Input Validation) and SI-16 (Memory Protection).
Threat & Defense at a Glance
Threat & Defense Details
Mitigating Controls (NIST 800-53 r5)AI
Timely flaw remediation through patching libbiosig directly eliminates the stack-based buffer overflow vulnerability in MFER parsing.
Information input validation enforces bounds checking on MFER file lengths and data before parsing to prevent buffer overflows.
Memory protection mechanisms like stack canaries, ASLR, and DEP mitigate exploitation of the stack-based buffer overflow for arbitrary code execution.
MITRE ATT&CK Enterprise TechniquesAI
Why these techniques?
Stack buffer overflow in MFER file parser directly enables RCE via crafted malicious file with no user interaction required.
NVD Description
A stack-based buffer overflow vulnerability exists in the MFER parsing functionality of The Biosig Project libbiosig 3.9.0 and Master Branch (35a819fa). A specially crafted MFER file can lead to arbitrary code execution. An attacker can provide a malicious file to…
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trigger this vulnerability.This vulnerability manifests on line 8744 of biosig.c on the current master branch (35a819fa), when the Tag is 3: else if (tag==3) { // character code char v[17]; // [1] if (len>16) fprintf(stderr,"Warning MFER tag2 incorrect length %i>16\n",len); curPos += ifread(&v,1,len,hdr); v[len] = 0; In this case, the overflowed buffer is the newly-declared `v` \[1\] instead of `buf`. Since `v` is only 17 bytes large, much smaller values of `len` (even those encoded using a single octet) can trigger an overflow in this code path.
Deeper analysisAI
A stack-based buffer overflow vulnerability, designated CVE-2025-54481 and published on 2025-08-25, affects the MFER parsing functionality in The Biosig Project's libbiosig version 3.9.0 and the master branch at commit 35a819fa. The issue occurs in biosig.c at line 8744, specifically in the code path handling tag==3, where a local char array v[17] is declared and read into using ifread(&v,1,len,hdr) without sufficient bounds checking. If len exceeds 16 bytes, this leads to a buffer overflow, enabling arbitrary code execution when processing a specially crafted MFER file. The vulnerability is classified under CWE-121 with 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).
Any attacker capable of supplying a malicious MFER file to an application using the affected libbiosig versions can exploit this vulnerability remotely with low complexity and no privileges or user interaction required. Successful exploitation allows arbitrary code execution on the target system, potentially leading to full compromise including high confidentiality, integrity, and availability impacts.
The primary advisory from Talos Intelligence (TALOS-2025-2234, available at https://talosintelligence.com/vulnerability_reports/TALOS-2025-2234) details the vulnerability discovery and code analysis but does not specify patches or mitigations in the provided information. Security practitioners should monitor for updates from The Biosig Project and review dependent applications that parse MFER files.
Details
- CWE(s)