Vulnerability · Published Aug 25, 2025 · Assigned by talos
CVE-2025-54481
Critical 9.8
In plain English
A critical-severity stack buffer overflow in libbiosig from The Biosig Project. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 0.7% (higher than 54% of all known vulnerabilities). Fixed versions are available - upgrade the affected package.
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 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.
Affected packages & fixed versions
| Ecosystem | Package | Fixed in | Advisory |
|---|---|---|---|
| Debian:12 | biosig | no fix listed | DEBIAN-CVE-2025-54481 |
| Debian:13 | biosig | no fix listed | DEBIAN-CVE-2025-54481 |
| Debian:14 | biosig | 3.9.5-1 | DEBIAN-CVE-2025-54481 |
| Ubuntu:25.10 | biosig | no fix listed | UBUNTU-CVE-2025-54481 |
| Ubuntu:26.10 | biosig | no fix listed | UBUNTU-CVE-2025-54481 |
Affected products (as reported)
| Vendor | Product | Versions |
|---|---|---|
| The Biosig Project | libbiosig | 3.9.0Master Branch (35a819fa) |
Weakness: CWE-121 · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H