CVE-2025-54486 in libbiosig
Summary
by MITRE • 08/25/2025
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 8824 of biosig.c on the current master branch (35a819fa), when the Tag is 11:
else if (tag==11) //0x0B {
// Fs if (len>6) fprintf(stderr,"Warning MFER tag11 incorrect length %i>6\n",len); double fval; curPos += ifread(buf,1,len,hdr);
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Analysis
by VulDB Data Team • 09/02/2025
The CVE-2025-54486 vulnerability represents a critical stack-based buffer overflow within the MFER file parsing component of the libbiosig library version 3.9.0 and earlier releases. This vulnerability resides in the biosig.c source file at line 8824 within the master branch commit 35a819fa, specifically when processing MFER tags with value 11, which corresponds to the sampling frequency field in medical file formats. The flaw occurs during the parsing of medical data files where the library fails to properly validate the length parameter before attempting to read data into a fixed-size buffer. The vulnerability is classified under CWE-121 as a stack-based buffer overflow, which directly enables arbitrary code execution when a maliciously crafted MFER file is processed by an application utilizing this library. This type of vulnerability falls under the ATT&CK technique T1059.007 for command and scripting interpreter, as successful exploitation would allow attackers to execute arbitrary commands on the victim system. The specific code path involves the conditional execution of tag 11 handling where the len parameter is checked against 6 bytes, but this validation is insufficient to prevent buffer overflows when the actual data exceeds the expected size.
The technical implementation of this vulnerability demonstrates a classic buffer management failure where the ifread function is called with a length parameter that is not adequately constrained before buffer operations occur. When the tag value equals 11, the code attempts to read len bytes into a buffer without proper bounds checking, allowing an attacker to craft an MFER file with a malicious length value that exceeds the allocated stack buffer space. The warning message indicates that the code recognizes potential length mismatches but fails to implement proper defensive measures. The vulnerability is particularly dangerous because it allows remote code execution through a simple file manipulation attack, requiring no special privileges or complex exploitation techniques. The attack surface is broad as any application that uses libbiosig for medical file processing could be affected, including medical imaging systems, research data analysis tools, and clinical data management platforms.
The operational impact of this vulnerability extends beyond simple code execution to encompass potential system compromise and data integrity violations in medical environments where libbiosig is commonly deployed. Attackers could leverage this vulnerability to gain unauthorized access to systems processing sensitive medical data, potentially leading to data breaches, system disruption, or further lateral movement within network environments. The vulnerability's exploitation requires minimal skill level and can be automated, making it particularly attractive to threat actors targeting healthcare organizations. Security professionals should note that this vulnerability aligns with ATT&CK tactic TA0001 (Initial Access) and TA0002 (Execution) as attackers could use this to establish persistence and execute malicious payloads. Organizations using affected versions of libbiosig must urgently implement mitigations, as the vulnerability could be exploited by both external attackers and insider threats. The impact is particularly severe in healthcare settings where medical device integrity and patient data protection are paramount, as this vulnerability could potentially compromise the reliability of medical diagnostic systems and patient monitoring equipment.
Mitigation strategies for CVE-2025-54486 should include immediate patching of libbiosig to version 3.9.1 or later where the buffer overflow has been addressed through proper bounds checking and length validation. System administrators should implement input validation measures at the application level to sanitize MFER file inputs before they reach the libbiosig library functions. Network segmentation and access controls should be enforced to limit exposure of systems that process medical data files, particularly those that utilize vulnerable versions of libbiosig. Security monitoring should include detection of unusual file processing patterns and potential attempts to trigger buffer overflow conditions. Organizations should also consider implementing application whitelisting policies that restrict execution of applications that may be vulnerable to this class of attack, following ATT&CK technique T1137.006 for application installation restrictions. Additionally, regular security assessments and penetration testing should be conducted to identify other potential buffer overflow vulnerabilities within medical device software ecosystems that may be similarly affected by improper input validation. The vulnerability serves as a reminder of the critical importance of secure coding practices in medical software development and the need for comprehensive security testing of components handling external data inputs.