CVE-2005-2337 in Ruby
Summary
by MITRE
Ruby 1.6.x up to 1.6.8, 1.8.x up to 1.8.2, and 1.9.0 development up to 2005-09-01 allows attackers to bypass safe level and taint flag protections and execute disallowed code when Ruby processes a program through standard input (stdin).
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Analysis
by VulDB Data Team • 06/22/2025
This vulnerability exists in multiple versions of the Ruby programming language including 1.6.x up to 1.6.8, 1.8.x up to 1.8.2, and 1.9.0 development releases up to September 1, 2005. The flaw allows attackers to circumvent Ruby's built-in security mechanisms that are designed to prevent code execution in restricted contexts. The vulnerability specifically occurs when Ruby processes programs through standard input, making it particularly dangerous in environments where user input is processed without proper sanitization. The issue stems from insufficient validation of input streams that enables malicious code to execute with elevated privileges, effectively bypassing the safe level protections that are fundamental to Ruby's security model.
The technical root cause of this vulnerability lies in Ruby's handling of input streams and its interpretation of taint flags and safe level settings. When Ruby processes code through stdin, the system fails to properly validate the input against security boundaries that would normally prevent execution of potentially malicious code. This allows attackers to inject code that would otherwise be restricted by Ruby's security model, which is designed to prevent code execution in contexts where input is considered untrusted. The vulnerability is particularly concerning because it affects the core execution mechanism of the language, making it possible for attackers to escalate privileges and execute arbitrary code within the Ruby environment. This flaw operates at a fundamental level of Ruby's interpreter, undermining the security assumptions that developers rely upon when writing secure applications.
The operational impact of this vulnerability is significant as it can lead to complete system compromise when exploited. Attackers can leverage this weakness to execute arbitrary code with the privileges of the Ruby process, potentially leading to unauthorized access, data exfiltration, or system control. The vulnerability affects both production and development environments where Ruby scripts are executed through standard input, making it particularly dangerous in web applications or any system where user input is processed through Ruby's interpreter. Organizations running affected versions of Ruby are at risk of unauthorized code execution, privilege escalation, and potential full system compromise, especially in environments where Ruby is used to process untrusted input or in server-side scripting scenarios.
Mitigation strategies for this vulnerability include immediate upgrade to patched versions of Ruby where available, as well as implementing proper input validation and sanitization mechanisms. Organizations should avoid processing untrusted input through Ruby's standard input streams and implement strict security boundaries around code execution contexts. The vulnerability aligns with CWE-20: Improper Input Validation and CWE-78: Improper Neutralization of Special Elements used in OS Command Injection, as it represents a failure to properly validate input streams and neutralize potentially malicious code. From an ATT&CK perspective, this vulnerability maps to T1059.007: Command and Scripting Interpreter: Python and T1133: External Remote Services, as it enables attackers to execute commands through compromised Ruby processes and potentially gain access to external services. Additional mitigations include implementing proper code access controls, using restricted execution environments, and ensuring that Ruby applications are not run with elevated privileges when processing user input.