CVE-2025-54487: A stack-based buffer overflow vulnerability exists in the MFER parsing functionality of The Biosig Project libbiosig 3.9.0 and Master Branch (35a819fa...

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 trigger this vulnerability.This vulnerability manifests on line 8842 of biosig.c on the current master branch (35a819fa), when the Tag is 12: else if (tag==12) //0x0C { // sampling resolution if (len>6) fprintf(stderr,"Warning MFER tag12 incorrect length %i>6\n",len); val32 = 0; int8_t v8; curPos += ifread(&UnitCode,1,1,hdr); curPos += ifread(&v8,1,1,hdr); curPos += ifread(buf,1,len-2,hdr); In addition to values of `len` greater than 130 triggering a buffer overflow, a value of `len` smaller than 2 will also trigger a buffer overflow due to an integer underflow when computing `len-2` in this code path.

Metrics

CVSS 3.1

9.8/10

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

EPSS Probability

0.64%

45.9th percentile

Probability of exploitation in the next 30 days. Learn more

Weakness Enumeration

CWE-121

Affected Software

Vendor	Product	Versions
Libbiosig Project	Libbiosig	< 3.9.1

References

https://talosintelligence.com/vulnerability_reports/TALOS-2025-2234Exploit, Third Party Advisory
https://www.talosintelligence.com/vulnerability_reports/TALOS-2025-2234

Timeline

Published: Aug 25, 2025
Last Modified: Jun 17, 2026
Status: Modified

Frequently Asked Questions

What is CVE-2025-54487?

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 trigger this vulnerability.This vulnerability manifests on line 8842 of biosig.c on the current master branch (35a819fa), when the Tag is 12: else if (tag==12) //0x0C { // sampling resolution if (len>6) fprintf(stderr,"Warning MFER tag12 incorrect length %i>6\n",len); val32 = 0; int8_t v8; curPos += ifread(&UnitCode,1,1,hdr); curPos += ifread(&v8,1,1,hdr); curPos += ifread(buf,1,len-2,hdr); In addition to values of `len` greater than 130 triggering a buffer overflow, a value of `len` smaller than 2 will also trigger a buffer overflow due to an integer underflow when computing `len-2` in this code path.

How severe is CVE-2025-54487?

CVE-2025-54487 has a CVSS score of 9.8/10 (CRITICAL severity). The EPSS model estimates a 0.64% probability of exploitation in the next 30 days.

How do I fix CVE-2025-54487?

Check the vendor references and advisories linked above for patched versions and mitigation guidance. You can also run a Strix scan to test if your systems are affected.