CVE-2016-20039 in Mess Emulator
Summary
by MITRE • 03/28/2026
Multi Emulator Super System 0.154-3.1 contains a buffer overflow vulnerability in the gamma parameter handling that allows local attackers to crash the application or execute arbitrary code. Attackers can supply an oversized gamma parameter value to overflow the stack buffer and overwrite the instruction pointer with a controlled address to achieve code execution.
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Analysis
by VulDB Data Team • 03/29/2026
The Multi Emulator Super System version 0.154-3.1 contains a critical buffer overflow vulnerability that resides in the gamma parameter handling mechanism of the application. This vulnerability represents a classic stack-based buffer overflow that occurs when the system fails to properly validate the length of user-supplied input parameters. The flaw specifically manifests during the processing of gamma values which are commonly used in graphics and display settings to adjust color intensity and brightness. When an attacker provides an oversized gamma parameter value, the system's input validation routines fail to restrict the data size, leading to unauthorized memory overwrite conditions.
The technical exploitation of this vulnerability leverages the fundamental principle of stack memory corruption where the oversized gamma parameter value exceeds the allocated buffer space, causing adjacent memory locations to be overwritten. This overflow specifically targets the instruction pointer register, which controls program execution flow, allowing attackers to redirect code execution to arbitrary memory locations. The vulnerability's impact extends beyond simple application crashes to full code execution capabilities, making it particularly dangerous for local attackers who can leverage this weakness to gain unauthorized system access. The stack-based nature of the overflow means that the attacker can precisely control the overwritten memory locations, including return addresses and function pointers, enabling sophisticated exploitation techniques.
From an operational perspective, this vulnerability creates significant security risks for systems running affected versions of Multi Emulator Super System. Local attackers who can execute code within the application's environment can exploit this flaw to escalate privileges, modify system files, or establish persistent backdoors. The vulnerability's accessibility through normal application usage means that any user with access to the system can potentially exploit it, making it particularly concerning for environments where multiple users share the same system resources. The impact is amplified by the fact that the application likely runs with elevated privileges during normal operation, providing attackers with additional attack surface. This vulnerability aligns with CWE-121 Stack-based Buffer Overflow, which specifically addresses buffer overflows that occur when insufficient bounds checking is performed on stack-based buffers.
The mitigation strategies for this vulnerability should focus on implementing robust input validation mechanisms and employing modern security practices such as stack canaries, address space layout randomization, and data execution prevention. Developers should immediately patch the gamma parameter handling code to include proper bounds checking and length validation for all user-supplied parameters. Additionally, implementing compile-time protections such as stack smashing protection and enabling compiler-based security features can significantly reduce the exploitability of similar vulnerabilities. Organizations should also consider network segmentation and privilege separation to limit the potential impact of successful exploitation attempts. This vulnerability demonstrates the importance of following secure coding practices and adhering to the principle of least privilege in software development, aligning with ATT&CK technique T1068 for Local Privilege Escalation and T1059 for Command and Scripting Interpreter usage in exploitation scenarios.