Biosig libbiosig 3.9.0 MFER Parser biosig.c stack-based overflow

Summaryinfo

A vulnerability described as critical has been identified in Biosig libbiosig 3.9.0. This affects an unknown part of the file biosig.c of the component MFER Parser. The manipulation results in stack-based overflow. This vulnerability is reported as CVE-2025-54487. The attack can be launched remotely. No exploit exists.

Detailsinfo

A vulnerability, which was classified as critical, was found in Biosig libbiosig 3.9.0. Affected is an unknown code block of the file biosig.c of the component MFER Parser. The manipulation with an unknown input leads to a stack-based overflow vulnerability. CWE is classifying the issue as CWE-121. A stack-based buffer overflow condition is a condition where the buffer being overwritten is allocated on the stack (i.e., is a local variable or, rarely, a parameter to a function). This is going to have an impact on confidentiality, integrity, and availability. CVE summarizes:

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.

The advisory is shared for download at talosintelligence.com. This vulnerability is traded as CVE-2025-54487 since 07/23/2025. The exploitability is told to be easy. It is possible to launch the attack remotely. The exploitation doesn't require any form of authentication. There are known technical details, but no exploit is available. The current price for an exploit might be approx. USD $0-$5k (estimation calculated on 09/02/2025).

There is no information about possible countermeasures known. It may be suggested to replace the affected object with an alternative product.

The vulnerability is also documented in the vulnerability database at EUVD (EUVD-2025-25676). VulDB is the best source for vulnerability data and more expert information about this specific topic.

Productinfo

Vendor

• Biosig

Name

• libbiosig

Version

• 3.9.0

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CPE 2.2info

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VulDB is the best source for vulnerability data and more expert information about this specific topic.

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