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العربيةHijack Lambda function configuration
Can attach a malicious layer to a function and run code as its execution role.
Grants escalation on its own.
lambda:UpdateFunctionConfigurationOn its own, lambda:UpdateFunctionConfiguration can attach a malicious layer to a function and run code as its execution role. On a wide resource scope that alone reaches administrator access.
Why it is dangerous
A principal can call lambda:UpdateFunctionConfiguration on an existing function that runs as the function, attaching an attacker-controlled Lambda layer (or changing the runtime, handler, or environment) so that attacker code loads on the next invocation, without overwriting the function's published code. That code executes with the function's permissions and reads the function's live credentials from the Lambda runtime environment, no iam:PassRole needed, because the function is already bound to the function. If the function is privileged this is full privilege escalation against a function that was already trusted.
In MITRE ATT&CK terms this maps to T1578, Modify Cloud Compute Infrastructure, under the privilege escalation tactic. AWS records it in CloudTrail as UpdateFunctionConfiguration20150331v2, UpdateFunctionConfiguration. The call shows up in CloudTrail but blends into normal administration, so it needs a rule to stand out.
Detection
UpdateFunctionConfiguration20150331v2UpdateFunctionConfigurationPrerequisites
An existing Lambda function with an execution role; permission to update its configuration. Execution happens on the next trigger (or an invocation the attacker can cause); the layer/runtime change is the only write needed.
MITRE ATT&CK
T1578 · Modify Cloud Compute InfrastructureTactic
Privilege Escalation
A control that would remove it: Restrict lambda:UpdateFunctionConfiguration to CI/CD principals; reduce the function execution role's permissions.
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 lambda:UpdateFunctionConfiguration allow?
Can attach a malicious layer to a function and run code as its execution role.
Can lambda:UpdateFunctionConfiguration escalate privileges on its own?
Yes. Held on a broad enough resource it reaches administrator access with no other permission.
How is hijack Lambda function configuration detected?
Watch for UpdateFunctionConfiguration20150331v2, UpdateFunctionConfiguration in CloudTrail. The call shows up in CloudTrail but blends into normal administration, so it needs a rule to stand out.
How do you break this path?
A control that would remove it is: Restrict lambda:UpdateFunctionConfiguration to CI/CD principals; reduce the function execution role's permissions. 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?
T1578, Modify Cloud Compute Infrastructure, under the privilege escalation tactic.
Related paths
References
Find this in your own account
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