Cross-Account IAM Assume Role Policy Without ExternalId or MFA
- Query id: 09c35abf-5852-4622-ac7a-b987b331232e
- Query name: Cross-Account IAM Assume Role Policy Without ExternalId or MFA
- Platform: Terraform
- Severity: Medium
- Category: Access Control
- URL: Github
Description¶
Cross-Account IAM Assume Role Policy should require external ID or MFA to protect cross-account access
Documentation
Code samples¶
Code samples with security vulnerabilities¶
Postitive test num. 1 - tf file
resource "aws_iam_role" "positive1" {
name = "test_role"
assume_role_policy = <<EOF
{
"Version": "2012-10-17",
"Statement": [
{
"Action": "sts:AssumeRole",
"Principal": {
"AWS": "arn:aws:iam::987654321145:root"
},
"Effect": "Allow",
"Resource": "*",
"Sid": ""
}
]
}
EOF
tags = {
tag-key = "tag-value"
}
}
Postitive test num. 2 - tf file
resource "aws_iam_role" "positive2" {
name = "test_role"
assume_role_policy = <<EOF
{
"Version": "2012-10-17",
"Statement": {
"Action": "sts:AssumeRole",
"Principal": {
"AWS": "arn:aws:iam::987654321145:root"
},
"Effect": "Allow",
"Resource": "*",
"Sid": "",
"Condition": {
"Bool": {
"aws:MultiFactorAuthPresent": "false"
}
}
}
}
EOF
tags = {
tag-key = "tag-value"
}
}
Postitive test num. 3 - tf file
resource "aws_iam_role" "positive3" {
name = "test_role"
assume_role_policy = <<EOF
{
"Version": "2012-10-17",
"Statement": {
"Action": "sts:AssumeRole",
"Principal": {
"AWS": "arn:aws:iam::987654321145:root"
},
"Effect": "Allow",
"Resource": "*",
"Sid": "",
"Condition": {
"StringEquals": {
"sts:ExternalId": ""
}
}
}
}
EOF
tags = {
tag-key = "tag-value"
}
}
Code samples without security vulnerabilities¶
Negative test num. 1 - tf file
resource "aws_iam_role" "negative1" {
name = "test_role"
assume_role_policy = <<EOF
{
"Version": "2012-10-17",
"Statement": [
{
"Action": "sts:AssumeRole",
"Principal": {
"AWS": "arn:aws:iam::987654321145:root"
},
"Effect": "Allow",
"Resource": "*",
"Sid": "",
"Condition": {
"StringEquals": {
"sts:ExternalId": "98765"
}
}
}
]
}
EOF
tags = {
tag-key = "tag-value"
}
}
Negative test num. 2 - tf file
resource "aws_iam_role" "negative2" {
name = "test_role"
assume_role_policy = <<EOF
{
"Version": "2012-10-17",
"Statement": [
{
"Action": "sts:AssumeRole",
"Principal": {
"AWS": "arn:aws:iam::987654321145:root"
},
"Effect": "Allow",
"Resource": "*",
"Sid": "",
"Condition": {
"Bool": {
"aws:MultiFactorAuthPresent": "true"
}
}
}
]
}
EOF
tags = {
tag-key = "tag-value"
}
}