CVE-2025-54489 Memory corruption in libbiosig
A stack-based buffer overflow in libbiosig allows arbitrary code execution via a specially crafted MFER file.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2025-54489?
CVE-2025-54489 is a critical memory corruption vulnerability in The Biosig Project libbiosig, published on 25 Aug 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official 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.
Weakness: CWE-121
Which versions are affected by CVE-2025-54489?
It affects 1 product.
Products include Libbiosig Project Libbiosig.
How do I fix CVE-2025-54489?
Apply the vendor's patch.
Upgrade to the fixed version. Memory-safe languages, compiler hardening and fuzzing prevent most new cases. More about Memory corruption.
Is CVE-2025-54489 being exploited?
There is no known exploitation of CVE-2025-54489 in the wild and no public exploit code.
Other vulnerabilities in The Biosig Project libbiosig
Sources
Also known as DEBIAN-CVE-2025-54489, GHSA-54vg-hcf2-vf9w, UBUNTU-CVE-2025-54489.