CVE-2026-51271 in ESP32-audioI2S
Summary
by MITRE • 07/28/2026
In schreibfaul1 ESP32-audioI2S 3.4.5, a heap-based buffer overflow vulnerability exists in the WAV header parsing function read_WAV_Header(). The function reads untrusted chunk size and bytes-to-skip value directly from malicious WAV files without reasonable range restriction. Abnormally large bts and headerSize values lead to out-of-bounds heap memory read/write during header parsing, which can be exploited to execute arbitrary code, disclose sensitive information, cause denial of service or escalate privileges.
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Analysis
by VulDB Data Team • 07/28/2026
The vulnerability under discussion affects schreibfaul1 ESP32-audioI2S library version 3.4.5, specifically within the WAV header parsing functionality implemented in the read_WAV_Header() function. This represents a critical heap-based buffer overflow condition that arises from inadequate input validation during audio file processing operations on embedded systems. The flaw manifests when the library processes maliciously crafted WAV files that contain oversized chunk size indicators and bytes-to-skip values, creating opportunities for adversaries to manipulate memory access patterns beyond intended boundaries.
The technical implementation of this vulnerability stems from the function's failure to enforce reasonable bounds checking on critical header parameters extracted from untrusted input streams. During WAV file parsing, the read_WAV_Header() routine directly consumes headerSize and bytes-to-skip values without performing sufficient validation to ensure these values remain within acceptable operational limits for heap memory allocation. When adversaries provide abnormally large values for bts and headerSize fields, the parsing logic attempts to allocate or access heap memory regions that exceed available boundaries, resulting in undefined behavior patterns including memory corruption, information disclosure, and potential code execution.
The operational impact of this vulnerability extends across multiple security domains including arbitrary code execution, information disclosure, and denial of service conditions. Attackers can leverage this flaw to execute malicious payloads within the constrained environment of ESP32 microcontrollers, potentially compromising audio processing applications that rely on this library for media file handling. The heap corruption resulting from out-of-bounds memory operations creates opportunities for privilege escalation attacks when the affected system operates with elevated permissions. Additionally, the vulnerability may enable information disclosure through memory read operations that access sensitive data residing in adjacent heap regions, while also providing denial of service capabilities by corrupting heap metadata structures.
This vulnerability aligns with CWE-121 heap-based buffer overflow classification and maps to ATT&CK technique T1059.007 for execution through audio processing components. The attack surface is particularly concerning given that ESP32 devices often operate in embedded environments where memory constraints limit the effectiveness of traditional exploit mitigations. Organizations deploying applications utilizing this library must consider implementing input validation controls, memory bounds checking, and proper error handling procedures to prevent exploitation. Recommended mitigation strategies include immediate library version updates, implementation of strict input parameter validation, heap memory sanitization routines, and application-level monitoring for anomalous memory access patterns during audio file processing operations.
The broader implications of this vulnerability highlight the critical need for robust input validation in embedded systems development, particularly when handling multimedia file formats that may contain variable-length headers with potentially malicious content. Given the widespread use of ESP32 platforms in IoT applications and embedded audio systems, this flaw represents a significant risk to device security and system integrity across numerous deployment scenarios where untrusted audio content processing is required.