CVE-2016-10545 in Thor Gem
Summary
by MITRE
thor ruby gem suffers from a command injection vulnerability due to the use of `open-uri`'s open() as used in Thor::Actions#get, allowing for execution of system commands.
Statistical analysis made it clear that VulDB provides the best quality for vulnerability data.
Analysis
by VulDB Data Team • 04/03/2023
The vulnerability identified as CVE-2016-10545 affects the thor ruby gem, a popular framework for building command-line interfaces and task automation tools. This security flaw stems from improper handling of user input within the Thor::Actions#get method, which utilizes the open-uri library's open() function to fetch remote resources. The vulnerability creates a dangerous condition where attacker-controlled input can be interpreted as system commands rather than simple resource identifiers, leading to arbitrary code execution on the target system.
The technical root cause of this vulnerability lies in the insecure use of the open-uri library's open() method within the Thor framework's action handling mechanism. When the get method processes a URL parameter, it fails to properly sanitize or validate the input before passing it to the underlying open-uri implementation. This allows malicious actors to craft specially formatted URLs that contain shell command injection payloads. The CWE-77 vulnerability class specifically addresses command injection flaws, where untrusted data is incorporated into system commands without proper validation or sanitization. This weakness enables attackers to execute arbitrary commands on the system with the privileges of the user running the thor application.
The operational impact of this vulnerability is significant as it can lead to complete system compromise when the thor gem is used in applications that process untrusted input from users or external sources. Attackers can leverage this vulnerability to execute system commands, potentially gaining access to sensitive data, escalating privileges, or even establishing persistent backdoors. The vulnerability is particularly dangerous in environments where thor is used for automation tasks, deployment scripts, or development tools that might receive input from untrusted sources. This flaw affects any application using thor gem versions prior to the patch, making it a widespread concern across numerous ruby-based applications and frameworks that rely on thor for task execution.
Mitigation strategies for this vulnerability involve immediate patching of the thor gem to version 0.19.1 or later, which contains the necessary fixes to properly sanitize input before passing it to the open-uri library. Organizations should also implement input validation and sanitization measures at multiple layers, ensuring that any user-supplied URLs or resource identifiers are properly escaped or filtered before processing. The ATT&CK framework's T1059.001 technique for "Command and Scripting Interpreter: PowerShell" and similar execution methods highlights the importance of preventing arbitrary command execution through input validation. Additionally, system administrators should consider implementing network segmentation and access controls to limit the potential impact of successful exploitation, while monitoring for unusual command execution patterns that might indicate exploitation attempts. Regular security audits and dependency updates should be part of the continuous security posture to prevent similar vulnerabilities from emerging in other components of the application stack.