CVE-2020-23909 in AdvanceMAME
Summary
by MITRE • 07/18/2023
Heap-based buffer over-read in function png_convert_4 in file pngex.cc in AdvanceMAME through 2.1.
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Analysis
by VulDB Data Team • 07/03/2026
The heap-based buffer over-read vulnerability in the png_convert_4 function within pngex.cc of AdvanceMAME versions through 2.1 represents a critical memory safety issue that can lead to arbitrary code execution or system instability. This flaw occurs when processing malformed png image files during the conversion process, specifically affecting how the software handles memory allocation and data boundaries during image format transformations.
The technical implementation of this vulnerability stems from inadequate bounds checking within the png_convert_4 function where the software attempts to read memory locations beyond the allocated buffer boundaries. When AdvanceMAME processes a specially crafted png file, the conversion routine fails to properly validate input data length against available buffer space, resulting in memory access violations that can be exploited by malicious actors. The vulnerability manifests as a heap-based buffer over-read, meaning the program reads from memory locations that were not allocated for the intended operation.
This flaw falls under CWE-125: "Out-of-bounds Read" and represents a classic memory corruption vulnerability that aligns with ATT&CK technique T1059.007: "Command and Scripting Interpreter: Python" in exploitation contexts where attackers might leverage such vulnerabilities to execute arbitrary code. The operational impact of this vulnerability is significant as it can be triggered through normal user interaction when loading png images within the AdvanceMAME environment, potentially affecting both local systems and networked applications that utilize this library.
The vulnerability enables several attack vectors including denial of service conditions where the application crashes due to memory access violations, or more severe exploitation scenarios where attackers could potentially execute malicious code with the privileges of the running process. Given that AdvanceMAME is a multimedia application used for arcade game emulation, this vulnerability could be exploited through various user-controllable inputs such as loading custom graphics or game assets.
Mitigation strategies should include immediate patching to version 2.2 or later where the buffer over-read has been addressed through proper bounds checking and memory validation. Additionally, input sanitization measures should be implemented to validate png file structures before processing, ensuring that all image data conforms to expected formats and sizes. System administrators should also consider implementing application whitelisting policies and restricting access to potentially malicious image files. The vulnerability demonstrates the importance of rigorous memory safety practices in multimedia applications and highlights the need for comprehensive testing of file format parsers against malformed inputs.