CVE-2026-105837 in libmikmod
Summary
by MITRE • 10/06/2026
libmikmod before 3.3.14 contains an integer overflow vulnerability in DSM_Load() in load_dsm.c that allows attackers to trigger heap buffer overflow via crafted track counts. Attackers can supply a DSM module whose numchn and numpat product wraps a 16-bit value, overwriting heap memory to cause crashes or potential code execution.
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Analysis
by VulDB Data Team • 10/06/2026
The vulnerability identified in libmikmod versions prior to 3.3.14 represents a critical security flaw rooted in improper integer arithmetic within the DSM module loader component. Specifically, the function DSM_Load located in load_dsm.c fails to validate input parameters before performing multiplication operations that determine memory allocation sizes. The core technical issue arises when an attacker supplies a maliciously crafted DSM audio module file where the product of the number of channels (numchn) and the number of patterns (numpat) exceeds the maximum value representable by a 16-bit unsigned integer. This arithmetic overflow causes the calculated buffer size to wrap around to a significantly smaller positive value than intended, leading directly to an insufficient memory allocation during runtime initialization.
This heap-based buffer overflow allows for arbitrary write operations in memory space allocated for audio processing structures. Because libmikmod is frequently used as a backend library by various multimedia applications and game engines that process user-supplied or downloaded media files, the attack surface extends beyond the library itself to any application integrating this vulnerable version. When the oversized data from the crafted module file is copied into the undersized heap buffer, it overwrites adjacent memory regions containing critical control structures such as function pointers, object headers, or other metadata. This corruption can lead to immediate application crashes due to segmentation faults or access violations, resulting in a denial of service condition for end users relying on affected software.
Beyond simple stability issues, the ability to overwrite heap memory with attacker-controlled data presents severe risks regarding code execution. By carefully crafting the input module file and potentially leveraging information leakage vulnerabilities present in other parts of the application stack, an adversary could manipulate program flow control mechanisms such as return addresses or virtual function tables. This capability aligns closely with Common Weakness Enumeration CWE-190 (Integer Overflow or Wraparound) which describes the root cause, and CWE-787 (Out-of-bounds Write) which characterizes the resulting memory corruption. The exploitation path typically involves tricking a victim into opening a malicious audio file within an application that utilizes libmikmod for playback, thereby triggering the vulnerable code path during the loading phase of the module.
From a threat intelligence perspective, this vulnerability maps to MITRE ATT&CK technique T1203 (Exploitation for Client Execution) if leveraged through social engineering tactics involving malicious media files. It also relates to CWE-476 (NULL Pointer Dereference) in scenarios where the overflow leads to null pointer access due to corrupted metadata, although code execution remains the primary high-severity concern. The lack of bounds checking on integer multiplication results is a common pitfall in C/C++ libraries handling binary formats with fixed-size headers, highlighting the necessity for rigorous input validation and use of safe arithmetic functions that detect overflows before allocation occurs.
Mitigation strategies primarily involve upgrading to libmikmod version 3.3.14 or later where this integer overflow has been patched by implementing proper range checks on numchn and numpat values prior to multiplication. For organizations unable to immediately update their dependencies, defensive coding practices such as using compiler-provided sanitizers like AddressSanitizer during development can help detect similar issues in other parts of the codebase. Additionally, application developers integrating libmikmod should implement strict validation rules for audio file headers and consider sandboxing media processing tasks to limit the impact of potential memory corruption events. Regular security audits focusing on integer arithmetic operations are recommended to prevent recurrence of such vulnerabilities in legacy or custom multimedia libraries.