Need

Prevention of unauthorized access to system exit functions

Context

• Usage of Ruby for building dynamic and object-oriented applications

Description

Non compliant code

        def shutdown_system
  exit
end
        
        

In the above code snippet, a method shutdown_system is defined which uses exit to terminate the application. This is a problematic coding practice in a Ruby on Rails web application.

The exit command in Ruby ends the current script being executed. In the context of a web application, this means it will attempt to shut down the application server. This is undesirable because it can lead to a denial-of-service (DoS) attack. An attacker could potentially exploit this functionality to shut down the application, making it unavailable to other users.

The exit command should not be used in a web application context. Instead, exceptions should be used to handle error conditions. If a serious error occurs that requires the application to be stopped, it should be logged and handled appropriately, but not by shutting down the entire application.

Steps

• Remove the 'shutdown_system' method that calls 'exit' function.
• Ensure that there are no other places in the code where 'exit' function is called.
• Replace the use of 'exit' function with appropriate error handling and graceful shutdown mechanisms.
• Implement a proper exception handling mechanism to handle errors and exceptions gracefully.
• Consider using a logging framework to log errors and exceptions instead of abruptly shutting down the application.
• Review the application's architecture and design to ensure that there are no other potential avenues for denial of service attacks.
• Regularly update and patch the application and its dependencies to mitigate any potential security vulnerabilities.

Compliant code

        # def shutdown_system
#   exit
# end
        
        

The above code represents a method shutdown_system that calls the exit function. This is a vulnerability in the application as it allows for a potential Denial of Service (DoS) attack. The exit function in Ruby ends the program immediately, which in a web application context, could lead to the shutdown of the application server.

To fix this vulnerability, the shutdown_system method should be removed or commented out as shown above. This will prevent the application from being shut down abruptly.

In addition, the application should implement proper error handling and graceful shutdown mechanisms. This could involve catching exceptions and handling them appropriately, rather than allowing them to crash the application.

A logging framework could also be used to log errors and exceptions. This would provide a record of any issues that occur, which could be useful for debugging and preventing future vulnerabilities.

Finally, the application's architecture and design should be reviewed to ensure that there are no other potential avenues for DoS attacks. This could involve checking for other uses of the exit function, as well as other potential vulnerabilities.

Regular updates and patches to the application and its dependencies can also help to mitigate any potential security vulnerabilities.

References

• 423. Inappropriate coding practices - System exit