ANS-C01 Question 444
Select 4Your organization is deploying a multi-tier web application on AWS. The architecture includes a public-facing Application Load Balancer (ALB) in front of an Amazon ECS service, which communicates with a relational database hosted on Amazon RDS in a private subnet. As part of your security review, you are tasked with identifying potential threats and implementing mitigations. Which of the following are valid threat models for this architecture?
- A
An attacker exploiting an unpatched vulnerability in the ECS container to access the RDS database
- B
A Distributed Denial of Service (DDoS) attack overwhelming the ALB
- C
Unauthorized access to the ECS service's IAM role to manipulate application-level permissions
- D
A malicious insider attempting to directly access the database from the private subnet
- E
A cross-site scripting (XSS) attack targeting the ALB to inject malicious code into the backend
Show answer and explanation
Correct answers: A, B, C, D
Explanation
This question evaluates your understanding of common threat models in a multi-tier architecture hosted on AWS. The architecture includes public-facing components, private subnets, IAM, and containerized workloads, each of which introduces potential attack vectors. Understanding these threats helps ensure the implementation of effective security mechanisms like patch management, DDoS protection, IAM role least privilege, and subnet-level access controls. XSS is not a valid threat model for the ALB because it does not process user-generated content directly.
- A. Correct.
Correct: If the ECS container has an unpatched vulnerability, an attacker could potentially exploit it to gain access to the underlying infrastructure or the database.
- B. Correct.
Correct: ALBs are public-facing and susceptible to DDoS attacks, which can cause service disruption if not mitigated.
- C. Correct.
Correct: If an attacker gains unauthorized access to the ECS service's IAM role, they could escalate privileges or manipulate application resources.
- D. Correct.
Correct: A malicious insider with access to the private subnet may attempt to directly connect to the RDS database, bypassing application-level controls.
- E. Incorrect.
Incorrect: ALBs do not process application content at the level required for XSS attacks; XSS attacks typically exploit vulnerabilities in the application itself, not the load balancer.