Overview
A critical OS command injection vulnerability, identified as CVE-2025-63916, has been discovered in MyScreenTools version 2.2.1.0. This flaw resides within the GIF compression tool and stems from insufficient sanitization of user-supplied file paths before they are passed to the operating system’s command interpreter (cmd.exe). This allows a malicious actor to inject and execute arbitrary system commands with the privileges of the user running the MyScreenTools application. This vulnerability poses a significant security risk as it can lead to complete system compromise.
Technical Details
The vulnerability is located in the CMD() function within the GIFSicleTool\Form_gif_sicle_tool.cs file. The application constructs shell commands by concatenating unsanitized user input (file paths, specifically input and output pathnames) and executes them using cmd.exe. Because the file paths are not properly validated or escaped, an attacker can inject malicious commands by crafting a file path containing shell commands. For example, a filename like "image.gif & calc.exe &" would execute the calculator application on Windows when MyScreenTools attempts to compress the GIF.
CVSS Analysis
Currently, a CVSS score for CVE-2025-63916 is not available (N/A). However, due to the nature of OS Command Injection vulnerabilities, which allow for arbitrary code execution, the vulnerability is likely to receive a high to critical CVSS score upon evaluation. It’s crucial to address this vulnerability immediately.
Possible Impact
The exploitation of this vulnerability can lead to severe consequences, including:
- Arbitrary Code Execution: Attackers can execute arbitrary system commands on the affected system.
- Data Breach: Sensitive data can be accessed, stolen, or modified.
- System Compromise: The entire system can be compromised, leading to loss of control and denial of service.
- Malware Installation: Attackers can install malware, such as ransomware or keyloggers, on the system.
- Privilege Escalation: Depending on the user’s privileges running the application, the attacker could escalate to system administrator privileges.
Mitigation or Patch Steps
Currently, a patch is not available. It’s highly recommended the following steps be taken immediately:
- Discontinue Use: Until a patch is released, discontinue the use of MyScreenTools v2.2.1.0, especially the GIF compression functionality.
- Contact Vendor: Contact the MyScreenTools vendor (luotengyuan) to request a security patch immediately.
- Input Validation (If Possible): If you have access to the code, implement robust input validation and sanitization on all user-supplied file paths before passing them to any shell commands. Ensure that file paths are properly escaped to prevent command injection.
- Principle of Least Privilege: If MyScreenTools must be used, run it under a user account with minimal privileges to limit the potential damage if the vulnerability is exploited.
References
Vulnerability Research Report
Vulnerable Code Snippet
MyScreenTools Repository
