terraform.lang.security.iam.no-iam-star-actions.no-iam-star-actions
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Ensure that no IAM policies allow "*" as a statement's actions. This allows all actions to be performed on the specified resources, and is a violation of the principle of least privilege. Instead, specify the actions that a certain user or policy is allowed to take.
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Defintion
rules:
- id: no-iam-star-actions
patterns:
- pattern-either:
- patterns:
- pattern-inside: |
resource $TYPE "..." {
...
policy = jsonencode({
...
Statement = [
...
]
...
})
...
}
- pattern-not-inside: |
resource $TYPE "..." {
...
policy = jsonencode({
...
Statement = [
...,
{... Effect = "Deny" ...},
...
]
...
})
...
}
- pattern-either:
- pattern: Action = "*"
- pattern: Action = ["*"]
- metavariable-pattern:
metavariable: $TYPE
pattern-either:
- pattern: |
"aws_iam_role_policy"
- pattern: |
"aws_iam_policy"
- pattern: |
"aws_iam_user_policy"
- pattern: |
"aws_iam_group_policy"
- patterns:
- pattern-inside: |
data aws_iam_policy_document "..." {
...
statement {
...
}
...
}
- pattern-not-inside: |
data aws_iam_policy_document "..." {
...
statement {
...
effect = "Deny"
...
}
...
}
- pattern: |
actions = ["*"]
message: Ensure that no IAM policies allow "*" as a statement's actions. This
allows all actions to be performed on the specified resources, and is a
violation of the principle of least privilege. Instead, specify the
actions that a certain user or policy is allowed to take.
metadata:
references:
- https://registry.terraform.io/providers/hashicorp/aws/latest/docs/resources/iam_policy
- https://github.com/bridgecrewio/checkov/blob/ca830e14745c2c8e1b941985f305abe985d7f1f9/checkov/terraform/checks/data/aws/StarActionPolicyDocument.py
category: security
cwe:
- "CWE-269: Improper Privilege Management"
license: Commons Clause License Condition v1.0[LGPL-2.1-only]
technology:
- terraform
- aws
owasp:
- A04:2021 - Insecure Design
subcategory:
- audit
likelihood: LOW
impact: LOW
confidence: LOW
vulnerability_class:
- Improper Authorization
languages:
- hcl
severity: WARNING
Examples
no-iam-star-actions.tf
resource "aws_iam_user_policy" "lb_ro" {
name = "test"
user = aws_iam_user.lb.name
# Terraform's "jsonencode" function converts a
# Terraform expression result to valid JSON syntax.
policy = jsonencode({
Version = "2012-10-17"
Statement = [
{
# ok: no-iam-star-actions
Action = [
"ec2:Describe*",
]
Effect = "Allow"
Resource = "*"
},
]
})
}
data aws_iam_policy_document "policy" {
statement {
# ok: no-iam-star-actions
actions = ["ec2:Describe"]
principals {
type = "AWS"
identifiers = ["*"]
}
resources = ["*"]
}
}
resource "aws_iam_policy" "policy" {
name = "test_policy"
path = "/"
description = "My test policy"
# Terraform's "jsonencode" function converts a
# Terraform expression result to valid JSON syntax.
policy = jsonencode({
Version = "2012-10-17"
Statement = [
{
#ruleid: no-iam-star-actions
Action = "*"
Effect = "Allow"
Resource = "s3"
},
]
})
}
resource "aws_iam_policy" "policy" {
name = "test_policy"
path = "/"
description = "My test policy"
# Terraform's "jsonencode" function converts a
# Terraform expression result to valid JSON syntax.
policy = jsonencode({
Version = "2012-10-17"
Statement = [
{
#ruleid: no-iam-star-actions
Action = ["*"]
Effect = "Allow"
Resource = "s3"
},
]
})
}
data aws_iam_policy_document "policy" {
statement {
# ruleid: no-iam-star-actions
actions = ["*"]
principals {
type = "AWS"
identifiers = ["*"]
}
resources = ["someResource"]
}
}
Short Link: https://sg.run/9rZ4