CVE-2026-51252 in ESP32-audioI2S
Summary
by MITRE • 07/28/2026
schreibfaul1 ESP32-audioI2S 3.4.5 has a buffer overflow vulnerability in the MP3Decoder::UnpackSFMPEG1 function due to missing input validation on attacker-controlled MP3 metadata.
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Analysis
by VulDB Data Team • 07/28/2026
The schreibfaul1 ESP32-audioI2S library version 3.4.5 contains a critical buffer overflow vulnerability within the MP3Decoder::UnpackSFMPEG1 function that stems from inadequate input validation of attacker-controlled MP3 metadata. This vulnerability represents a classic example of improper input validation where the software fails to properly sanitize or verify the length and structure of incoming audio metadata before processing it. The flaw occurs during the decoding process when the system attempts to unpack MPEG-1 frame headers without sufficient bounds checking on the metadata fields that define frame parameters.
The technical implementation of this vulnerability allows an attacker to craft malicious MP3 files containing oversized or malformed metadata values that exceed the allocated buffer space within the UnpackSFMPEG1 function. When the library processes these crafted files, the insufficient input validation causes data to be written beyond the intended memory boundaries, potentially overwriting adjacent memory locations and leading to unpredictable behavior including application crashes, memory corruption, or even arbitrary code execution. This type of vulnerability falls under CWE-121 which specifically addresses stack-based buffer overflow conditions where insufficient bounds checking allows attackers to overwrite adjacent memory.
The operational impact of this vulnerability is significant for any system utilizing the ESP32-audioI2S library for MP3 playback, particularly in IoT devices, embedded audio systems, or applications that accept user-uploaded audio content. Attackers could exploit this weakness by uploading malicious MP3 files through web interfaces, file transfer protocols, or any other means that allow arbitrary content ingestion. The vulnerability is particularly concerning because it operates at the decoding level where legitimate audio processing occurs, making exploitation more difficult to detect and distinguish from normal application behavior.
From a cybersecurity perspective, this vulnerability aligns with ATT&CK technique T1203 which involves exploiting software vulnerabilities to gain unauthorized access or execute malicious code. The attack surface expands when considering that many IoT devices using ESP32 microcontrollers are deployed in environments where external input is common and security controls may be limited. The buffer overflow could potentially be leveraged for privilege escalation, denial of service attacks, or as a stepping stone for more sophisticated exploitation techniques. Organizations should consider this vulnerability in their risk assessment frameworks, particularly those with embedded systems that process user-generated audio content.
Mitigation strategies include immediate code updates to implement proper input validation and bounds checking within the MP3Decoder::UnpackSFMPEG1 function, ensuring that all metadata values are verified against expected ranges before processing. Additional protective measures involve implementing memory protection mechanisms such as stack canaries, address space layout randomization, and input sanitization routines that validate file headers and frame parameters prior to decoding operations. System administrators should also consider network segmentation and access controls to limit the potential impact of exploitation, while monitoring for unusual audio processing patterns that might indicate malicious payload attempts.