User authentication and authorization in SCADA systems - Practice Problems & Coding Challenges

Challenge - 5 Problems

🧠 Conceptual

intermediate

Understanding Authentication vs Authorization

Which statement correctly describes the difference between authentication and authorization in a SCADA system?

A Authentication and authorization both verify the user's identity only.

B Authentication determines what the user can access; authorization verifies who the user is.

C Authorization is done before authentication in the access process.

D Authentication verifies who the user is; authorization determines what the user can access.

💡 Hint

Think about logging in first, then checking permissions.

Authentication confirms the user's identity, while authorization checks their permissions.

💻 Command Output

intermediate

Result of User Login Command

What is the output of the following SCADA system command when a user enters correct credentials?

SCADA systems

login --user=operator --password=correctpass

A Login failed: User not found.

B Error: Invalid password.

C Login successful: Access granted to operator dashboard.

D System error: Unable to connect to authentication server.

💡 Hint

Correct credentials should allow access.

When credentials are correct, the system grants access and confirms login success.

❓ Configuration

advanced

Configuring Role-Based Access Control (RBAC)

Which configuration snippet correctly assigns the 'engineer' role permission to modify control parameters in a SCADA system?

A

[roles]
engineer=read,write,view_only

B

[roles]
engineer=read,write,modify_controls

C

[roles]
engineer=read,execute_scripts

D

[roles]
engineer=read,write,delete_logs

💡 Hint

Look for permissions that include modifying controls.

The 'modify_controls' permission allows the engineer role to change control parameters, which is required.

❓ Troubleshoot

advanced

Diagnosing Access Denied Error

A user with the 'technician' role tries to access the alarm settings but receives 'Access Denied'. Which is the most likely cause?

A The technician role lacks permission to modify alarm settings.

B The user's password has expired.

C The SCADA system is offline.

D The user is not authenticated.

💡 Hint

Consider role permissions related to the requested resource.

Access denied usually means the role does not have the required permission, not authentication or system status issues.

🔀 Workflow

expert

Correct Sequence for Secure User Access Setup

What is the correct order of steps to securely set up a new user in a SCADA system?

A 1,2,3,4

B 2,1,3,4

C 3,1,2,4

D 1,3,2,4

💡 Hint

Think about creating the user first, then assigning roles, then setting password, then testing.

The user must be created first, then roles assigned, password set, and finally tested to ensure access.

Practice

1. What is the main purpose of user authentication in a SCADA system?

easy

A. To backup system data

B. To confirm the identity of a user

C. To monitor system performance

D. To control what actions a user can perform

Solution

1. Step 1: Understand authentication concept

   User authentication is about verifying who the user is.

2. Step 2: Differentiate from authorization

   Authorization controls permissions, not identity confirmation.

3. Final Answer:

   To confirm the identity of a user -> Option B

4. Quick Check:

   Authentication = Confirm identity [OK]

Hint: Authentication = Who you are, Authorization = What you can do [OK]

Common Mistakes:

• Confusing authentication with authorization
• Thinking authentication controls permissions
• Mixing system monitoring with user identity

2. Which of the following is the correct syntax to define a user role with read-only access in a SCADA system configuration file?

easy

A. role read_only { permissions: ["read"] }

B. role read_only = permissions: read

C. role: read_only { access = read }

D. read_only role { permissions = read }

Solution

1. Step 1: Identify correct role syntax

   The correct syntax uses 'role' keyword, role name, and permissions list in braces.

2. Step 2: Check option formats

   role read_only { permissions: ["read"] } correctly uses braces and array syntax for permissions.

3. Final Answer:

   role read_only { permissions: ["read"] } -> Option A

4. Quick Check:

   Correct role syntax uses braces and permission array [OK]

Hint: Look for braces and array syntax for permissions [OK]

Common Mistakes:

• Using '=' instead of ':' for permissions
• Missing braces around role definition
• Incorrect order of keywords

3. Given the following SCADA user permissions code snippet:

user = { name: "operator", roles: ["read_only", "control"] }
roles = {
  read_only: { permissions: ["read"] },
  control: { permissions: ["write", "execute"] }
}

What permissions does the user "operator" have?

medium

A. ["read"]

B. ["write", "execute"]

C. ["read", "write", "execute"]

D. ["read", "write"]

Solution

1. Step 1: Identify roles assigned to user

   User "operator" has roles "read_only" and "control".

2. Step 2: Combine permissions from both roles

   "read_only" grants ["read"], "control" grants ["write", "execute"]. Combined permissions are ["read", "write", "execute"].

3. Final Answer:

   ["read", "write", "execute"] -> Option C

4. Quick Check:

   Combine all role permissions for user [OK]

Hint: Add permissions from all user roles together [OK]

Common Mistakes:

• Selecting permissions from only one role
• Forgetting to merge permissions
• Confusing role names with permissions

4. A SCADA system admin tries to assign a user a role using this command:
assign_role user1 admin
But the system returns an error: "Role 'admin' not found." What is the most likely cause?

medium

A. The role 'admin' is not defined in the system

B. The user 'user1' does not exist

C. The command syntax is incorrect

D. The system is offline

Solution

1. Step 1: Analyze error message

   Error says "Role 'admin' not found," indicating the role is missing.

2. Step 2: Check command and user existence

   Command syntax looks correct and error does not mention user, so user likely exists.

3. Final Answer:

   The role 'admin' is not defined in the system -> Option A

4. Quick Check:

   Error message points to missing role [OK]

Hint: Check error message for missing role or user [OK]

Common Mistakes:

• Assuming user does not exist without checking
• Blaming command syntax without error details
• Ignoring error message content

5. In a SCADA system, you want to restrict a user so they can only read data but not control devices. Which approach best achieves this?

hard

A. Disable user authentication for faster access

B. Assign the user multiple roles including control

C. Grant the user admin privileges temporarily

D. Assign the user a role with only read permissions

Solution

1. Step 1: Understand requirement

   User must only read data, no control allowed.

2. Step 2: Choose role assignment

   Assigning a role with only read permissions restricts actions properly.

3. Step 3: Evaluate other options

   Assigning control roles or admin privileges contradicts restriction; disabling authentication is insecure.

4. Final Answer:

   Assign the user a role with only read permissions -> Option D

5. Quick Check:

   Restrict actions by role permissions [OK]

Hint: Use roles with minimal permissions to restrict users [OK]

Common Mistakes:

• Giving users more permissions than needed
• Disabling authentication to simplify access
• Using admin roles for normal users