CVE-2025-61043: Monkey's Audio Buffer Overflow Flaw

CVE-2025-61043 Overview

An out-of-bounds read vulnerability has been discovered in Monkey's Audio 11.31, specifically in the CAPECharacterHelper::GetUTF16FromUTF8 function. The issue arises from improper handling of the length of the input UTF-8 string, causing the function to read past the memory boundary. This vulnerability may result in a crash or expose sensitive data.

Critical Impact

This out-of-bounds read vulnerability in Monkey's Audio could lead to application crashes (denial of service) or potential exposure of sensitive information from memory when processing maliciously crafted audio files or UTF-8 strings.

Affected Products

• Monkey's Audio version 11.31

Discovery Timeline

• 2025-10-28 - CVE-2025-61043 published to NVD
• 2025-10-30 - Last updated in NVD database

Technical Details for CVE-2025-61043

Vulnerability Analysis

This vulnerability is classified as CWE-125 (Out-of-Bounds Read), a memory corruption flaw that occurs when a program reads data from a memory location that is outside the intended buffer boundaries. In the case of Monkey's Audio 11.31, the vulnerable function CAPECharacterHelper::GetUTF16FromUTF8 fails to properly validate the length of input UTF-8 strings before processing them.

When the function attempts to convert UTF-8 encoded strings to UTF-16 format, it does not adequately check the boundaries of the input buffer. This allows an attacker to supply a specially crafted input that causes the function to read beyond the allocated memory region. The consequences include potential application crashes due to accessing invalid memory, as well as the possibility of leaking sensitive information that may reside in adjacent memory locations.

Root Cause

The root cause of this vulnerability lies in the improper bounds checking within the CAPECharacterHelper::GetUTF16FromUTF8 function. The function processes UTF-8 input strings without adequately validating the string length against the buffer size before performing read operations. This missing or insufficient validation allows the function to continue reading memory beyond the intended buffer boundary when processing malformed or deliberately oversized UTF-8 input.

Attack Vector

This vulnerability has a network-based attack vector, meaning it can potentially be exploited remotely without requiring prior authentication or user interaction. An attacker could craft a malicious audio file or input containing specially formed UTF-8 strings that trigger the out-of-bounds read condition when processed by the vulnerable Monkey's Audio application. The attack does not require elevated privileges, making it accessible to unauthenticated attackers.

The exploitation scenario involves delivering a malformed APE audio file or input data to a system running the vulnerable version of Monkey's Audio. When the application attempts to process the UTF-8 string conversion, the vulnerable function reads past the buffer boundary, potentially causing a crash or exposing memory contents.

Detection Methods for CVE-2025-61043

Indicators of Compromise

• Unexpected crashes or termination of Monkey's Audio application during file processing
• Memory access violation errors in system logs related to Monkey's Audio processes
• Abnormal memory read patterns when processing APE format audio files

Detection Strategies

• Monitor for abnormal process behavior including unexpected crashes of Monkey's Audio application
• Implement file integrity monitoring for APE audio files being processed by the application
• Deploy memory protection mechanisms such as ASLR and DEP to detect exploitation attempts
• Utilize endpoint detection tools to identify memory access violations in the application

Monitoring Recommendations

• Enable crash reporting and analysis for Monkey's Audio processes
• Monitor system event logs for application faults related to audio processing
• Implement network traffic analysis to detect potentially malicious APE files being transferred to systems running vulnerable software

How to Mitigate CVE-2025-61043

Immediate Actions Required

• Update Monkey's Audio to a patched version when available from the vendor
• Restrict processing of untrusted APE audio files on systems running Monkey's Audio 11.31
• Consider temporarily disabling or uninstalling the vulnerable application until a patch is available
• Implement network-level filtering to block potentially malicious APE files from reaching vulnerable systems

Patch Information

As of the last update, no official patch information has been published. Users should monitor the official Monkey's Audio website and the Vulnerability Report for updates on remediation efforts. Organizations should plan to apply security updates as soon as they become available from the vendor.

Workarounds

• Avoid processing APE audio files from untrusted or unknown sources
• Isolate systems running Monkey's Audio 11.31 from network exposure where possible
• Run the application in a sandboxed environment to limit the impact of potential exploitation
• Implement application whitelisting to prevent unauthorized or modified versions of Monkey's Audio from executing

# Configuration example: Restrict file associations for APE files (Windows)
# Remove file type association temporarily
assoc .ape=
# Or redirect to a safer handler until patched