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Race condition

Description​

The system presents unexpected behavior when the inputs of a specific functionality do not arrive in the expected order.

Impact​

  • Overwrite, delete or read arbitrary files from the system.
  • Cause unexpected behaviour in the application.

Recommendation​

Ensure that the verification and use of inputs must be realized at the same time or in an atomic way.

Threat​

Anonymous attacker in the system.

Expected Remediation Time​

⌚ 30 minutes.

Score​

Default score using CVSS 3.1. It may change depending on the context of the vulnerability.

Base​

  • Attack vector: L
  • Attack complexity: L
  • Privileges required: N
  • User interaction: N
  • Scope: U
  • Confidentiality: L
  • Integrity: L
  • Availability: N

Temporal​

  • Exploit code madurity: P
  • Remediation level: X
  • Report confidence: R

Result​

  • Vector string: CVSS:3.1/AV:L/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N/E:P/RL:X/RC:R
  • Score:
    • Base: 5.1
    • Temporal: 4.7
  • Severity:
    • Base: Medium
    • Temporal: Medium

Code Examples​

Compliant code​

The application uses inputs under a proper method to avoid issues

public static void main(String[] args) {
  Scanner input = new UserInput(*args);
  String username = input.userId;
  String password = input.password;

  try {
    if(username.equals(username) && password.equals(password)){
      ScheduledExecutorService executor = Executors.newScheduledThreadPool(2);
      users check = new users(username, password);
      signIn(user, check);
    }
  } catch (InterruptedException e) {
    //Code to catch exception when log in is not successful
  }
}

Non compliant code​

If the input comes in an unexpected order, the application can not fulfill the requirements

public static void main(String[] args) {
  Scanner input = new Scanner(System.in);
  String username = input.next();
  String password = input.next();

  try {
    if(username.equals(username) && password.equals(password)){
      ScheduledExecutorService executor = Executors.newScheduledThreadPool(2);
      users check = new users(username, password);
      signIn(user, check);
    }
  } catch (InterruptedException e) {
    //Code that could be executed even when the data is right, if for some reason, the client side sends it in a wrong order
  }
}

Requirements​

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