Unsanitized user input in OS command

• Rule ID: ruby_lang_exec_using_user_input
• Languages: ruby
• Source: exec_using_user_input.yml

Description

Applications should not execute OS commands that are formed from user input. This rule checks for external commands containing user-supplied data.

Remediations

❌ Avoid using user input when executing commands:

system(params[:command])

✅ Use user input indirectly when executing commands:

command =
  case params[:action]
  when "option1"
    "command1"
  when "option2"
    "command2"
  end

system(command)

Resources

• OWASP Ruby command injection cheat sheet
• OWASP OS command injection cheat sheet

Associated CWE

• CWE-78: Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')

OWASP Top 10

• A03:2021 - Injection

Configuration

To skip this rule during a scan, use the following flag

bearer scan /path/to/your-project/ --skip-rule=ruby_lang_exec_using_user_input

To run only this rule during a scan, use the following flag

bearer scan /path/to/your-project/ --only-rule=ruby_lang_exec_using_user_input