CVE-2020-37013: Audio Playback Recorder Buffer Overflow

CVE-2020-37013 Overview

Audio Playback Recorder 3.2.2 contains a local buffer overflow vulnerability in the eject and registration parameters that allows attackers to execute arbitrary code. Attackers can craft malicious payloads and overwrite Structured Exception Handler (SEH) to execute shellcode when pasting specially crafted input into the application's input fields.

Critical Impact

This vulnerability enables local attackers to achieve arbitrary code execution by exploiting a stack-based buffer overflow and SEH overwrite, potentially leading to complete system compromise on affected Windows systems.

Affected Products

• Audio Playback Recorder version 3.2.2

Discovery Timeline

• 2026-01-29 - CVE CVE-2020-37013 published to NVD
• 2026-01-29 - Last updated in NVD database

Technical Details for CVE-2020-37013

Vulnerability Analysis

This vulnerability is classified as CWE-121 (Stack-based Buffer Overflow), a memory corruption flaw that occurs when an application writes data beyond the boundaries of a fixed-size stack buffer. In Audio Playback Recorder 3.2.2, the eject and registration input fields fail to properly validate the length of user-supplied data before copying it to a stack buffer. This lack of bounds checking allows an attacker to overflow the buffer and corrupt adjacent memory, including critical control structures like the Structured Exception Handler (SEH) chain.

The attack requires local access and user interaction, as the victim must paste specially crafted malicious input into one of the vulnerable fields. Once triggered, the overflow corrupts the SEH pointer, and when an exception is subsequently raised, control flow is redirected to attacker-controlled shellcode.

Root Cause

The root cause of this vulnerability is improper input validation in the eject and registration parameter handling routines. The application allocates a fixed-size buffer on the stack and copies user input without verifying that the input length does not exceed the buffer capacity. This classic programming error enables attackers to write past the buffer boundary, overwriting return addresses and exception handler pointers stored on the stack.

Attack Vector

The attack vector is local, requiring the attacker to either have direct access to the target system or to socially engineer a victim into pasting malicious content into the vulnerable application fields. The exploitation process involves:

1. Crafting a payload containing padding to reach the SEH pointer offset
2. Overwriting the SEH chain with pointers to a POP-POP-RET gadget
3. Placing shellcode in a predictable location relative to the overwritten pointers
4. Triggering an exception to invoke the corrupted exception handler
5. Gaining code execution when the shellcode runs with the privileges of the application

The vulnerability mechanism relies on SEH overwrite techniques common in Windows exploitation. Detailed technical information and a proof-of-concept exploit are available in the Exploit-DB #48796 entry. Additional findings and demonstration can be found in the Whitecr0wz Findings Image.

Detection Methods for CVE-2020-37013

Indicators of Compromise

• Presence of Audio Playback Recorder version 3.2.2 installed on endpoints
• Anomalous crash logs or exception reports from AudioPlaybackRecorder.exe
• Suspicious shellcode patterns in process memory associated with the application
• Unexpected child processes spawned from the Audio Playback Recorder application

Detection Strategies

• Monitor for buffer overflow exploitation patterns using endpoint detection and response (EDR) solutions
• Deploy application whitelisting to prevent execution of unauthorized code
• Utilize behavioral analysis to detect SEH manipulation attempts and unusual exception handling behavior
• Configure Windows Defender Exploit Guard or similar protections with SEHOP (Structured Exception Handler Overwrite Protection) enabled

Monitoring Recommendations

• Enable detailed Windows Event logging for application crashes and exceptions
• Monitor for suspicious clipboard activity involving large amounts of data being pasted into legacy applications
• Implement memory protection monitoring to detect stack corruption attempts
• Review endpoint telemetry for indicators of post-exploitation activity following application crashes

How to Mitigate CVE-2020-37013

Immediate Actions Required

• Remove or disable Audio Playback Recorder 3.2.2 from all systems where it is installed
• Consider migrating to alternative audio recording software that is actively maintained and receives security updates
• Enable Windows exploit mitigations such as SEHOP, DEP (Data Execution Prevention), and ASLR (Address Space Layout Randomization) system-wide
• Restrict local access to systems where the vulnerable application must remain installed

Patch Information

No vendor patch is currently available for this vulnerability. Audio Playback Recorder appears to be legacy software that is no longer actively maintained. Organizations should consider this software end-of-life and plan for migration to supported alternatives. For additional context, the software archive is available at Internet Archive Software, and a security advisory is published by VulnCheck Security Advisory.

Workarounds

• Uninstall Audio Playback Recorder 3.2.2 and use alternative audio recording software
• If removal is not immediately possible, restrict access to the application to only trusted administrators
• Enable Enhanced Mitigation Experience Toolkit (EMET) or Windows Defender Exploit Guard with SEH overwrite protection
• Run the application in an isolated virtual machine or sandboxed environment to limit potential impact

# Enable SEHOP system-wide via registry (Windows)
reg add "HKLM\SYSTEM\CurrentControlSet\Control\Session Manager\kernel" /v DisableExceptionChainValidation /t REG_DWORD /d 0 /f