430 – Serverless - one dedicated IAM role per function
Description
Avoid sharing IAM roles with multiple Lambda functions. As permissions are added to the role, these are shared across all functions using this role. By using one dedicated IAM role per function, you can control permissions more intentionally.
Impact
Execute actions that should be restricted to other groups or roles.
Recommendation
Every Lambda function should have a 1:1 relationship with an IAM role. Even if some functions have the same policy initially, always separate the IAM roles to ensure least privilege policies.
Threat
Authenticated attacker from the Internet with access to a misconfigured role.
Expected Remediation Time
Score 4.0
Default score using CVSS 4.0. It may change depending on the context of the src.
Base 4.0
- Attack vector: N
- Attack complexity: H
- Attack Requirements: N
- Privileges required: H
- User interaction: N
- Confidentiality (VC): L
- Integrity (VI): L
- Availability (VA): N
- Confidentiality (SC): N
- Integrity (SI): N
- Availability (SA): N
Threat 4.0
- Exploit maturity: U