CVE-2019-8355 in SoX
Summary
by MITRE
An issue was discovered in SoX 14.4.2. In xmalloc.h, there is an integer overflow on the result of multiplication fed into the lsx_valloc macro that wraps malloc. When the buffer is allocated, it is smaller than expected, leading to a heap-based buffer overflow in channels_start in remix.c.
Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.
Analysis
by VulDB Data Team • 07/10/2023
The vulnerability identified as CVE-2019-8355 represents a critical integer overflow flaw within the SoX audio processing library version 14.4.2. This issue stems from improper handling of memory allocation calculations within the xmalloc.h header file where multiplication operations are fed into the lsx_valloc macro that ultimately wraps the standard malloc function. The flaw creates a scenario where the calculated buffer size exceeds the maximum representable value for the integer type used in the calculation, resulting in an unexpectedly small memory allocation. This integer overflow condition occurs during the dynamic memory allocation process and directly impacts the subsequent heap memory management within the audio processing pipeline.
The technical exploitation of this vulnerability manifests in the channels_start function located within remix.c, where the heap-based buffer overflow occurs due to the insufficiently allocated memory buffer. When the application processes audio channels and attempts to allocate memory for channel data structures, the integer overflow causes the system to allocate a buffer that is significantly smaller than required for proper operation. This discrepancy between allocated and expected buffer sizes creates a condition where subsequent memory writes overflow into adjacent heap memory regions, potentially corrupting other data structures or enabling arbitrary code execution. The flaw demonstrates characteristics consistent with CWE-190, Integer Overflow or Wraparound, which specifically addresses issues where integer arithmetic results in values that exceed the maximum representable value for the data type.
The operational impact of CVE-2019-8355 extends beyond simple memory corruption, as it represents a potential vector for remote code execution within applications that utilize SoX for audio processing tasks. Attackers could leverage this vulnerability by crafting specially formatted audio files or processing commands that trigger the vulnerable code path, leading to heap memory corruption that may be exploited to execute malicious code with the privileges of the affected application. The vulnerability affects systems where SoX is used for processing audio content, particularly in environments where untrusted audio files are processed, such as media servers, audio editing applications, or content filtering systems. The flaw's exploitation requires a specific code path involving channel processing operations, making it less likely to be triggered by casual usage but still presents a significant security risk in automated or batch processing scenarios.
Mitigation strategies for CVE-2019-8355 should prioritize immediate patching of the SoX library to version 14.4.3 or later, which contains the necessary fixes for the integer overflow condition. System administrators should also implement input validation measures to restrict processing of audio files from untrusted sources and consider deploying heap memory protection mechanisms such as stack canaries, address space layout randomization, and heap integrity checks. Additionally, organizations should conduct security assessments to identify all systems utilizing vulnerable versions of SoX and establish monitoring procedures to detect potential exploitation attempts. The vulnerability aligns with ATT&CK technique T1059.007 for Command and Scripting Interpreter: Unix Shell, as exploitation may involve crafting specific audio inputs to trigger the memory corruption. Organizations should also consider implementing network segmentation and access controls to limit exposure of systems that process audio content, particularly those that may be exposed to untrusted inputs or remote attack vectors.