CVE-2025-54481: 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 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.

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

0.66%

46.8th 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-2025-54481?

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 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.

How severe is CVE-2025-54481?

CVE-2025-54481 has a CVSS score of 9.8/10 (CRITICAL severity). The EPSS model estimates a 0.66% probability of exploitation in the next 30 days.

How do I fix CVE-2025-54481?

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.