CVE-2017-7742 in libsndfile
Summary
by MITRE
In libsndfile before 1.0.28, an error in the "flac_buffer_copy()" function (flac.c) can be exploited to cause a segmentation violation (with read memory access) via a specially crafted FLAC file during a resample attempt, a similar issue to CVE-2017-7585.
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Analysis
by VulDB Data Team • 11/29/2022
The vulnerability identified as CVE-2017-7742 affects the libsndfile library version 1.0.27 and earlier, representing a critical memory safety issue that can lead to arbitrary code execution or system instability. This flaw resides within the flac_buffer_copy() function located in the flac.c source file, which is part of the widely used audio processing library that handles various audio file formats including FLAC. The vulnerability specifically manifests during resampling operations when processing malformed FLAC files, making it particularly dangerous in applications that process user-supplied audio content or perform automatic format conversions.
The technical implementation of this vulnerability stems from improper bounds checking and memory management within the FLAC decoding logic. When the flac_buffer_copy() function attempts to copy data from a specially crafted FLAC file, it fails to properly validate buffer boundaries, leading to a read memory access violation that results in a segmentation fault. This type of flaw falls under the CWE-125 vulnerability category, which specifically addresses out-of-bounds read conditions that can occur when software accesses memory beyond the intended buffer limits. The vulnerability is particularly insidious because it requires only a single malformed audio file to trigger the memory corruption, making it suitable for exploitation in both local and remote attack scenarios.
The operational impact of CVE-2017-7742 extends across numerous applications that depend on libsndfile for audio processing, including but not limited to media players, audio editing software, content management systems, and digital audio workstations. Attackers can leverage this vulnerability through social engineering tactics by distributing malicious audio files that appear legitimate but contain crafted data structures designed to exploit the buffer overflow condition. The segmentation fault that occurs during resampling operations can cause application crashes, potentially leading to denial of service conditions, or in more sophisticated exploitation attempts, could provide attackers with opportunities to execute arbitrary code with the privileges of the affected application. This vulnerability aligns with ATT&CK technique T1059.007, which covers the use of command and scripting interpreters, as it can be exploited through audio file processing pipelines that may inadvertently execute malicious code during format conversion operations.
The exploitation of this vulnerability demonstrates a classic example of how audio processing libraries can become attack vectors in modern computing environments where multimedia content is frequently processed and converted. Applications using libsndfile without proper input validation become susceptible to this attack, particularly those that automatically process or convert audio files from untrusted sources. The similarity to CVE-2017-7585 indicates that this represents a broader class of issues within the FLAC decoding implementation, suggesting that developers should examine other related functions within the same codebase for similar vulnerabilities. Security practitioners should prioritize updating affected systems to libsndfile version 1.0.28 or later, which includes proper bounds checking and memory validation mechanisms that prevent the out-of-bounds read conditions that lead to segmentation faults. Additionally, implementing input validation and sanitization measures at the application level can provide defense-in-depth protection against potential exploitation attempts.