CVE-2025-55037: TkEasyGUI OS Command Injection RCE Flaw

CVE-2025-55037 Overview

CVE-2025-55037 is a critical OS Command Injection vulnerability affecting TkEasyGUI, a Python library that simplifies GUI development using Tkinter. The vulnerability allows remote unauthenticated attackers to execute arbitrary operating system commands when the application is configured to construct messages from external sources.

TkEasyGUI is designed to make GUI programming easier by providing a simplified interface to Tkinter functionality. However, improper neutralization of special elements in user-supplied input creates a dangerous attack surface that can lead to complete system compromise.

Critical Impact

Remote unauthenticated attackers can execute arbitrary OS commands on affected systems, potentially leading to complete system takeover, data exfiltration, or further lateral movement within the network.

Affected Products

• TkEasyGUI versions prior to v1.0.22
• Python applications using vulnerable TkEasyGUI versions with external input processing
• Systems where TkEasyGUI is configured to construct messages from external sources

Discovery Timeline

• 2025-09-05 - CVE-2025-55037 published to NVD
• 2025-09-05 - Last updated in NVD database

Technical Details for CVE-2025-55037

Vulnerability Analysis

This vulnerability is classified as CWE-78: Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection'). The flaw exists in how TkEasyGUI processes external input when constructing messages or executing system-level operations.

When applications built with TkEasyGUI are configured to accept and process data from external sources (such as user input, network data, or file contents), the library fails to properly sanitize special characters and command sequences. This allows attackers to inject malicious OS commands that are then executed with the privileges of the running application.

The network-based attack vector with no authentication requirements makes this vulnerability particularly dangerous in internet-facing applications or services that utilize TkEasyGUI for their graphical interface components.

Root Cause

The root cause of CVE-2025-55037 lies in insufficient input validation and sanitization within TkEasyGUI's message construction routines. The library does not properly neutralize shell metacharacters and command separators (such as ;, |, &, $(), and backticks) before passing user-controlled data to system command execution functions.

This oversight allows attackers to break out of the intended command context and inject additional commands that will be executed by the underlying operating system shell.

Attack Vector

The vulnerability is exploitable over the network without requiring authentication or user interaction. An attacker can craft malicious input containing embedded OS commands and submit it to an application using a vulnerable version of TkEasyGUI. When the application processes this input to construct messages or perform operations, the injected commands are executed on the underlying system.

The attack surface includes any application endpoint that accepts external input and processes it through the vulnerable TkEasyGUI components. This could include form inputs, file uploads, API endpoints, or any other data ingestion point that ultimately feeds into TkEasyGUI's message handling functionality.

Due to the nature of command injection vulnerabilities, successful exploitation can result in complete system compromise, allowing attackers to read sensitive files, modify system configurations, install malware, or pivot to other systems on the network.

Detection Methods for CVE-2025-55037

Indicators of Compromise

• Unexpected child processes spawned from Python applications using TkEasyGUI
• Unusual system commands executed with the privileges of GUI applications
• Network connections from TkEasyGUI-based applications to suspicious external IP addresses
• Log entries showing malformed or suspicious input patterns containing shell metacharacters

Detection Strategies

• Monitor process creation events for suspicious command execution originating from Python GUI processes
• Implement application-level logging to capture all external input processed by TkEasyGUI components
• Deploy network intrusion detection signatures for common command injection payloads
• Use endpoint detection and response (EDR) solutions to identify anomalous behavior from GUI applications

Monitoring Recommendations

• Enable comprehensive logging for all applications using TkEasyGUI
• Configure alerts for process trees showing unusual command execution patterns
• Monitor outbound network traffic from systems running vulnerable applications
• Implement file integrity monitoring on critical system files that could be targets of post-exploitation

How to Mitigate CVE-2025-55037

Immediate Actions Required

• Upgrade TkEasyGUI to version v1.0.22 or later immediately
• Audit all applications using TkEasyGUI to identify those processing external input
• Implement input validation at the application level as a defense-in-depth measure
• Consider temporarily disabling external input processing functionality until patching is complete

Patch Information

The vulnerability has been addressed in TkEasyGUI version v1.0.22. Users should upgrade to this version or later to remediate the vulnerability. The patch is available through the GitHub Release v1.0.22.

For additional technical details and security advisory information, refer to the JVN Security Advisory JVN48739895.

Workarounds

• Restrict network access to applications using vulnerable TkEasyGUI versions using firewall rules
• Implement strict input validation and sanitization at the application layer before passing data to TkEasyGUI
• Run TkEasyGUI-based applications with minimal system privileges to limit the impact of successful exploitation
• Consider using application sandboxing or containerization to isolate vulnerable applications

# Upgrade TkEasyGUI to patched version
pip install --upgrade tkeasygui>=1.0.22

# Verify installed version
pip show tkeasygui | grep Version