User data for EC2 instances must not contain sensitive AWS keys
Default Severity: critical
Explanation
EC2 instance data is used to pass start up information into the EC2 instance. This userdata must not contain access key credentials. Instead use an IAM Instance Profile assigned to the instance to grant access to other AWS Services.
Possible Impact
User data is visible through the AWS Management console
Suggested Resolution
Remove sensitive data from the EC2 instance user-data generated by launch templates
Insecure Example
The following example will fail the aws-autoscaling-no-secrets-in-user-data check.
resource "aws_launch_template" "bad_example" {
image_id = "ami-12345667"
instance_type = "t2.small"
user_data = <<EOF
export AWS_ACCESS_KEY_ID=AKIAIOSFODNN7EXAMPLE
export AWS_SECRET_ACCESS_KEY=wJalrXUtnFEMI/K7MDENG/bPxRfiCYEXAMPLEKEY
export AWS_DEFAULT_REGION=us-west-2
EOF
}
Secure Example
The following example will pass the aws-autoscaling-no-secrets-in-user-data check.
resource "aws_iam_instance_profile" "good_example" {
// ...
}
resource "aws_launch_template" "good_example" {
image_id = "ami-12345667"
instance_type = "t2.small"
iam_instance_profile {
name = aws_iam_instance_profile.good_profile.arn
}
user_data = <<EOF
export GREETING=hello
EOF
}