CVE-2026-51259 in ESP32-audioI2S
Summary
by MITRE • 07/28/2026
Unchecked unsigned integer overflow in buffer size calculation in schreibfaul1 ESP32-audioI2S 3.4.5 leads to undersized PSRAM buffer allocation. Subsequent normal audio buffer read and write operations cause heap out-of-bounds access, memory corruption, denial of service, and potential code execution.
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Analysis
by VulDB Data Team • 07/28/2026
The vulnerability under discussion involves an unchecked unsigned integer overflow within the buffer size calculation mechanism of schreibfaul1 ESP32-audioI2S library version 3.4.5. This flaw manifests in the improper handling of buffer allocation parameters that directly impacts the allocation of PSRAM buffers used for audio processing operations. The specific technical issue occurs when calculating buffer sizes where unsigned integer overflow conditions are not properly validated, resulting in incorrect buffer sizing decisions.
The core technical flaw stems from a lack of input validation and overflow checking during arithmetic operations that determine buffer dimensions. When the library calculates the appropriate buffer size for PSRAM allocation, it performs mathematical operations on unsigned integers without verifying that these operations remain within valid bounds. This condition creates a scenario where legitimate buffer size calculations can produce values that wrap around to zero or extremely small values due to the nature of unsigned integer arithmetic. The CWE-190 classification applies here as this represents an integer overflow vulnerability that directly impacts memory allocation decisions.
The operational impact of this vulnerability extends beyond simple memory corruption to encompass multiple security and stability concerns. When heap out-of-bounds access occurs during normal audio buffer read and write operations, the system experiences unpredictable behavior including potential crashes, memory corruption, and complete denial of service conditions. The undersized buffer allocation means that subsequent legitimate audio processing operations attempt to access memory regions beyond the allocated buffer boundaries, creating opportunities for both accidental system instability and deliberate exploitation.
The memory corruption resulting from heap out-of-bounds access can lead to various security implications including potential code execution if attackers can control the data being written to these corrupted memory regions. This vulnerability represents a classic example of how seemingly benign buffer management issues can escalate into serious security concerns, particularly in embedded systems where memory corruption often translates directly into system compromise. The ATT&CK framework's T1068 (Exploitation for Privilege Escalation) and T1499 (Endpoint Denial of Service) techniques may be applicable depending on the specific exploitation scenario.
Mitigation strategies should focus on implementing proper integer overflow checking mechanisms within the buffer size calculation functions, ensuring that all arithmetic operations are validated against reasonable bounds before proceeding with memory allocation. The library code must perform explicit checks to prevent unsigned integer overflow conditions from occurring during buffer size calculations. Additionally, input validation should be strengthened to reject invalid parameters that could lead to problematic buffer sizing decisions, while proper error handling should be implemented to gracefully manage allocation failures rather than allowing the system to proceed with corrupted buffer configurations.