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 8970 of biosig.c on the current master branch (35a819fa), when the Tag is 63:

else if (tag==63) {
uint8_t tag2=255, len2=255;

count = 0;
while ((count<len) && !(FlagInfiniteLength && len2==0 && tag2==0)){
curPos += ifread(&tag2,1,1,hdr);
curPos += ifread(&len2,1,1,hdr);
if (VERBOSE_LEVEL==9)
fprintf(stdout,"MFER: tag=%3i chan=%2i len=%-4i tag2=%3i len2=%3i curPos=%i %li count=%4i\n",tag,chan,len,tag2,len2,curPos,iftell(hdr),(int)count);

if (FlagInfiniteLength && len2==0 && tag2==0) break;

count += (2+len2);
curPos += ifread(&buf,1,len2,hdr);

Here, the number of bytes read is not the Data Length decoded from the current frame in the file (`len`) but rather is a new length contained in a single octet read from the same input file (`len2`). Despite this, a stack-based buffer overflow condition can still occur, as the destination buffer is still `buf`, which has a size of only 128 bytes, while `len2` can be as large as 255.
Published: 2025-08-25
Score: 9.8 Critical
EPSS: < 1% Very Low
KEV: No
Impact: n/a
Action: n/a
AI Analysis

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Remediation

No vendor fix or workaround currently provided.

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Tracking

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Advisories
Source ID Title
EUVD EUVD EUVD-2025-25674 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 8970 of biosig.c on the current master branch (35a819fa), when the Tag is 63: else if (tag==63) { uint8_t tag2=255, len2=255; count = 0; while ((count<len) && !(FlagInfiniteLength && len2==0 && tag2==0)){ curPos += ifread(&tag2,1,1,hdr); curPos += ifread(&len2,1,1,hdr); if (VERBOSE_LEVEL==9) fprintf(stdout,"MFER: tag=%3i chan=%2i len=%-4i tag2=%3i len2=%3i curPos=%i %li count=%4i\n",tag,chan,len,tag2,len2,curPos,iftell(hdr),(int)count); if (FlagInfiniteLength && len2==0 && tag2==0) break; count += (2+len2); curPos += ifread(&buf,1,len2,hdr); Here, the number of bytes read is not the Data Length decoded from the current frame in the file (`len`) but rather is a new length contained in a single octet read from the same input file (`len2`). Despite this, a stack-based buffer overflow condition can still occur, as the destination buffer is still `buf`, which has a size of only 128 bytes, while `len2` can be as large as 255.
History

Mon, 03 Nov 2025 19:30:00 +0000

Type Values Removed Values Added
References

Tue, 02 Sep 2025 16:45:00 +0000

Type Values Removed Values Added
First Time appeared Libbiosig Project
Libbiosig Project libbiosig
CPEs cpe:2.3:a:libbiosig_project:libbiosig:*:*:*:*:*:*:*:*
Vendors & Products Libbiosig Project
Libbiosig Project libbiosig

Mon, 25 Aug 2025 22:15:00 +0000

Type Values Removed Values Added
First Time appeared The Biosig Project
The Biosig Project libbiosig
Vendors & Products The Biosig Project
The Biosig Project libbiosig

Mon, 25 Aug 2025 21:45:00 +0000

Type Values Removed Values Added
Metrics ssvc

{'options': {'Automatable': 'yes', 'Exploitation': 'none', 'Technical Impact': 'total'}, 'version': '2.0.3'}

Mon, 25 Aug 2025 14:00:00 +0000

Type Values Removed Values Added
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 8970 of biosig.c on the current master branch (35a819fa), when the Tag is 63: else if (tag==63) { uint8_t tag2=255, len2=255; count = 0; while ((count<len) && !(FlagInfiniteLength && len2==0 && tag2==0)){ curPos += ifread(&tag2,1,1,hdr); curPos += ifread(&len2,1,1,hdr); if (VERBOSE_LEVEL==9) fprintf(stdout,"MFER: tag=%3i chan=%2i len=%-4i tag2=%3i len2=%3i curPos=%i %li count=%4i\n",tag,chan,len,tag2,len2,curPos,iftell(hdr),(int)count); if (FlagInfiniteLength && len2==0 && tag2==0) break; count += (2+len2); curPos += ifread(&buf,1,len2,hdr); Here, the number of bytes read is not the Data Length decoded from the current frame in the file (`len`) but rather is a new length contained in a single octet read from the same input file (`len2`). Despite this, a stack-based buffer overflow condition can still occur, as the destination buffer is still `buf`, which has a size of only 128 bytes, while `len2` can be as large as 255.
Weaknesses CWE-121
References
Metrics cvssV3_1

{'score': 9.8, 'vector': 'CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H'}

Subscriptions

Libbiosig Project Libbiosig
The Biosig Project Libbiosig
cve-icon MITRE

Status: PUBLISHED

Assigner: talos

Published:

Updated: 2025-11-03T18:13:30.624Z

Reserved: 2025-07-23T14:45:55.835Z

Link: CVE-2025-54489

cve-icon Vulnrichment

Updated: 2025-08-25T19:03:08.278Z

cve-icon NVD

Status : Modified

Published: 2025-08-25T14:15:35.233

Modified: 2025-11-03T19:16:10.860

Link: CVE-2025-54489

cve-icon Redhat

No data.

cve-icon OpenCVE Enrichment

Updated: 2025-08-25T21:53:11Z

Weaknesses