CVE-2026-51273 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 ID3 tag parsing function showID3Tag() of the embedded audio streaming library. The program reads untrusted long ID3 tag value from malicious audio files and uses unbounded appendf() to write formatted strings into ps_ptr heap buffer without length validation. Successful exploitation allows attackers to execute arbitrary code, leak sensitive memory data, cause device crash, or escalate privileges via a crafted malicious audio file.
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Analysis
by VulDB Data Team • 07/28/2026
The vulnerability in schreibfaul1 ESP32-audioI2S version 3.4.5 represents a critical heap-based buffer overflow that emerges during the parsing of ID3 tags within embedded audio streaming applications. This flaw resides in the showID3Tag() function which processes metadata from audio files, specifically targeting the handling of untrusted ID3 tag values. The security issue stems from the library's use of an unbounded appendf() function that writes formatted strings into a heap buffer designated as ps_ptr without implementing any length validation checks. This design oversight creates a pathway for attackers to manipulate audio files with excessively long ID3 tag values, thereby triggering memory corruption during the parsing process.
The technical exploitation of this vulnerability occurs when maliciously crafted audio files contain oversized ID3 tag data that exceeds the allocated heap buffer size. The unbounded appendf() operation allows arbitrary data to be written beyond the intended buffer boundaries, leading to memory overwrite conditions that can corrupt adjacent heap allocations. This type of heap corruption typically manifests through memory addresses being overwritten with attacker-controlled values, enabling potential code execution at privilege levels matching the audio processing application. The vulnerability's impact extends beyond simple crashes to include information disclosure, where sensitive memory contents may be leaked through controlled data overwrites, and privilege escalation opportunities when the application operates with elevated system permissions.
From a cybersecurity perspective, this vulnerability aligns with CWE-122 heap-based buffer overflow classification and maps directly to attack techniques described in the MITRE ATT&CK framework under T1059 for command and scripting interpreter and T1068 for exploit for privilege escalation. The embedded nature of ESP32 devices combined with this vulnerability creates a particularly concerning threat landscape, as these systems often operate in resource-constrained environments where memory management is critical. The exploitation requires minimal prerequisites beyond crafting a malicious audio file, making it accessible to attackers with basic file manipulation capabilities while potentially affecting a wide range of IoT and embedded audio applications that rely on this library.
Organizations utilizing this library should implement immediate mitigations including updating to patched versions of the ESP32-audioI2S library where buffer length validation has been implemented in the ID3 tag parsing functions. The recommended approach involves enforcing strict bounds checking on all ID3 tag values before processing, implementing input sanitization routines, and applying memory protection mechanisms such as stack canaries or address space layout randomization. Additionally, network segmentation and access controls should be reinforced to limit exposure of vulnerable systems to untrusted audio file inputs, while regular security audits should verify that no other similar buffer overflow vulnerabilities exist within the application's codebase or dependent libraries.