CVE-2016-20037 in xWPE
Summary
by MITRE • 03/28/2026
xwpe 1.5.30a-2.1 and prior contains a stack-based buffer overflow vulnerability that allows local attackers to execute arbitrary code by supplying overly long input strings that exceed buffer boundaries. Attackers can craft malicious command-line arguments with 262 bytes of junk data followed by shellcode to overwrite the instruction pointer and achieve code execution or denial of service.
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Analysis
by VulDB Data Team • 05/06/2026
The vulnerability identified as CVE-2016-20037 represents a critical stack-based buffer overflow in xwpe versions 1.5.30a-2.1 and earlier, presenting a significant security risk for systems utilizing this software. This flaw exists within the command-line argument processing mechanism where the application fails to properly validate input length before copying data into fixed-size buffers. The vulnerability specifically affects local attackers who can exploit this weakness through carefully crafted malicious inputs, making it particularly dangerous in environments where untrusted users have access to the system.
The technical implementation of this buffer overflow stems from improper input validation and inadequate bounds checking within the xwpe application's argument parsing code. When command-line arguments are processed, the software attempts to copy user-supplied data into a stack-allocated buffer without verifying that the input length exceeds the allocated buffer size. This classic programming error creates a condition where 262 bytes of junk data can be followed by shellcode, allowing attackers to overwrite the instruction pointer and redirect program execution flow. The vulnerability maps directly to CWE-121 Stack-based Buffer Overflow, which is classified as a fundamental weakness in memory safety that enables arbitrary code execution.
The operational impact of this vulnerability extends beyond simple privilege escalation, as it provides attackers with the capability to execute arbitrary code with the privileges of the affected process. Local attackers can leverage this weakness to gain unauthorized access to system resources, potentially leading to complete system compromise. The attack vector requires minimal sophistication, as the exploit involves crafting a specific input pattern with 262 bytes of padding followed by shellcode, making it accessible to attackers with moderate technical skills. Additionally, the vulnerability can result in denial of service conditions, where the application crashes due to corrupted execution flow, disrupting legitimate system operations and potentially creating availability issues for users relying on the software.
Mitigation strategies for this vulnerability should prioritize immediate patching of affected xwpe installations to version 2.1.1 or later, which contains the necessary fixes for the buffer overflow condition. System administrators should also implement input validation measures at the application level to prevent overly long arguments from being processed, while monitoring for suspicious command-line patterns that might indicate exploitation attempts. The implementation of stack protection mechanisms such as stack canaries and address space layout randomization can provide additional defense-in-depth measures against exploitation attempts. Organizations should also consider implementing principle of least privilege controls to limit the impact of potential exploitation, ensuring that the affected application runs with minimal necessary permissions. This vulnerability demonstrates the importance of proper input validation and buffer management practices in software development, aligning with ATT&CK technique T1059.001 for command and script interpreter execution, where attackers leverage such vulnerabilities to establish persistent access through crafted inputs that bypass normal security controls.