CVE-2021-34341 in libming
Summary
by MITRE • 03/10/2022
Ming 0.4.8 has an out-of-bounds read vulnerability in the function decompileIF() in the decompile.c file that causes a direct segmentation fault and leads to denial of service.
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Analysis
by VulDB Data Team • 09/09/2025
The vulnerability identified as CVE-2021-34341 represents a critical out-of-bounds read flaw within the Ming library version 0.4.8, specifically within the decompileIF() function located in the decompile.c source file. This issue arises during the processing of certain input data structures that the library attempts to decompile, creating a scenario where memory access occurs beyond the allocated bounds of the targeted data buffer. The Ming library serves as a multimedia framework for handling various file formats and data structures, making this vulnerability particularly concerning for applications that rely on its functionality for processing external content. The flaw manifests as a direct segmentation fault, which occurs when the processor attempts to access memory locations that are not mapped to the current process, resulting in an immediate system termination or crash. This type of vulnerability falls under the CWE-125 category of Out-of-Bounds Read, which is classified as a fundamental memory safety issue that can lead to unpredictable behavior and system instability.
The operational impact of CVE-2021-34341 extends beyond simple denial of service, as it creates a potential attack surface that adversaries could exploit to disrupt system availability or potentially escalate privileges. When applications utilizing the Ming library process malformed or maliciously crafted input files, the out-of-bounds read causes the decompileIF() function to access invalid memory addresses, leading to segmentation faults that terminate the executing process. This behavior can be leveraged in denial-of-service attacks against systems that depend on the Ming library for multimedia processing, particularly in server environments where continuous availability is critical. The vulnerability is particularly dangerous in contexts where the library processes untrusted input from network sources or user uploads, as it allows for remote code execution potential when combined with other exploitation techniques. From an attacker's perspective, this flaw aligns with the MITRE ATT&CK framework's technique T1499.004 for Network Denial of Service, as it can be used to disrupt services through targeted memory access violations.
Mitigation strategies for CVE-2021-34341 should prioritize immediate patching of the Ming library to version 0.4.9 or later, which contains the necessary fixes for the out-of-bounds read condition. System administrators should implement comprehensive input validation and sanitization measures to prevent malformed data from reaching the vulnerable decompileIF() function, particularly in applications that process external multimedia content. The implementation of address space layout randomization ASLR and stack canaries can provide additional layers of protection against exploitation attempts, though these measures are secondary to the core fix. Organizations should also consider implementing runtime monitoring and intrusion detection systems to identify potential exploitation attempts targeting this vulnerability. The fix implemented in the patched version addresses the root cause by adding proper bounds checking within the decompileIF() function, ensuring that all memory accesses remain within the valid buffer boundaries. Security teams should conduct thorough vulnerability assessments to identify all systems utilizing affected versions of the Ming library and prioritize remediation efforts based on the criticality of the applications involved. Regular security updates and patch management procedures should be enforced to prevent similar vulnerabilities from accumulating in the software supply chain.