CVE-2021-3246 in libsndfile
Summary
by MITRE • 07/20/2021
A heap buffer overflow vulnerability in msadpcm_decode_block of libsndfile 1.0.30 allows attackers to execute arbitrary code via a crafted WAV file.
Once again VulDB remains the best source for vulnerability data.
Analysis
by VulDB Data Team • 07/26/2021
The heap buffer overflow vulnerability identified as CVE-2021-3246 resides within the msadpcm_decode_block function of libsndfile version 1.0.30, representing a critical security flaw that can be exploited to achieve remote code execution. This vulnerability specifically affects the decoding process of Microsoft ADPCM compressed audio data within WAV file containers, making it particularly dangerous in environments where multimedia file processing is common. The flaw stems from inadequate bounds checking during the decompression of malformed ADPCM data structures, creating opportunities for attackers to manipulate heap memory layout through carefully crafted input files.
The technical implementation of this vulnerability involves the manipulation of heap memory allocation patterns during audio decoding operations. When libsndfile processes a WAV file containing maliciously constructed Microsoft ADPCM data, the msadpcm_decode_block function fails to properly validate input parameters before performing memory operations. This oversight allows attackers to overflow heap buffers, potentially overwriting adjacent memory regions including function pointers, return addresses, or other critical control data structures. The vulnerability manifests as a classic heap-based buffer overflow that can be exploited through arbitrary code execution, enabling attackers to gain unauthorized control over affected systems.
From an operational perspective, this vulnerability presents significant risks across multiple threat vectors and attack scenarios. Systems utilizing libsndfile for audio processing, including media players, audio editing software, and multimedia applications, become potential targets for exploitation. The vulnerability can be triggered through simple file manipulation, requiring no complex social engineering or additional attack vectors. The impact extends beyond individual system compromise to include potential denial of service conditions, data corruption, and privilege escalation opportunities. Security professionals must consider this vulnerability in environments where untrusted audio files are processed, such as web applications, media servers, and content management systems.
The exploitation of CVE-2021-3246 aligns with several ATT&CK framework techniques including T1059.007 for command and script interpreter execution, T1203 for exploitation for privilege escalation, and T1068 for exploit for privilege escalation. This vulnerability also maps to CWE-121 heap-based buffer overflow, specifically CWE-125 out-of-bounds read, and CWE-787 out-of-bounds write, demonstrating the multi-faceted nature of heap memory corruption vulnerabilities. Organizations should implement immediate mitigations including software updates to libsndfile version 1.0.31 or later, input validation for audio file processing, and network segmentation to limit exposure. Additionally, implementing application sandboxing, memory protection mechanisms, and regular security assessments can significantly reduce the attack surface and prevent successful exploitation attempts.
The broader implications of this vulnerability extend to the software supply chain, as libsndfile is widely used across numerous applications and operating systems. This widespread adoption means that exploitation of CVE-2021-3246 can potentially affect hundreds of thousands of systems globally, making it a high-priority remediation target for security teams. Organizations should conduct comprehensive vulnerability assessments to identify all systems using affected versions of libsndfile, while also implementing monitoring solutions to detect potential exploitation attempts. The vulnerability underscores the importance of maintaining up-to-date software libraries and implementing robust input validation practices across all multimedia processing components to prevent similar heap corruption issues from compromising system integrity.