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العربيةPass role to Lambda
Can pass a role to a new Lambda function and run code as it.
Grants escalation only in combination. All of these are needed together:
iam:PassRolelambda:CreateFunctioniam:PassRole can pass a role to a new Lambda function and run code as it, but only when it is held together with lambda:CreateFunction. Held together they reach administrator access.
Why it is dangerous
A principal holds iam:PassRole on the target role together with lambda:CreateFunction, so it can create a new Lambda function with the target role attached and invoke it, the function's code then runs with the target role's permissions. Because the target role trusts lambda.amazonaws.com AWS accepts the pass; if the target role is privileged this is full privilege escalation (arbitrary run-as-role code execution from a single create+invoke).
In MITRE ATT&CK terms this maps to T1648, Serverless Execution, under the privilege escalation tactic. AWS records it in CloudTrail as CreateFunction, Invoke. The call is loud in CloudTrail and stands out from normal activity.
Detection
CreateFunctionInvokePrerequisites
Target role's trust policy must allow lambda.amazonaws.com.
MITRE ATT&CK
T1648 · Serverless ExecutionTactic
Privilege Escalation
A control that would remove it: Remove iam:PassRole for this role or scope it with iam:PassedToService.
Whether to apply it depends on how the permission is used in your environment, so it is a business decision rather than an automatic fix. The same permission can be load-bearing in one account and pure risk in another.
Pathbreak confirms whether this path resolves in your account, ranks it against the others by how much it opens up, and uses your threat model and business context to show which paths are worth cutting.
Questions
What does iam:PassRole allow?
Can pass a role to a new Lambda function and run code as it.
What else is needed for iam:PassRole to be dangerous?
It becomes an escalation only when held together with lambda:CreateFunction. On its own it is not enough, which is what makes the combination easy to miss.
How is pass role to Lambda detected?
Watch for CreateFunction, Invoke in CloudTrail. The call is loud in CloudTrail and stands out from normal activity.
How do you break this path?
A control that would remove it is: Remove iam:PassRole for this role or scope it with iam:PassedToService. Whether to apply it depends on how the permission is used in your account, so it is a business decision rather than an automatic fix.
Which MITRE ATT&CK technique is this?
T1648, Serverless Execution, under the privilege escalation tactic.
Related paths
References
Find this in your own account
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