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العربيةExfiltrate through S3 replication
Can configure replication to copy a bucket out to an attacker bucket.
Grants escalation only in combination. All of these are needed together:
s3:PutReplicationConfigurationiam:PassRoles3:PutReplicationConfiguration can configure replication to copy a bucket out to an attacker bucket, but only when it is held together with iam:PassRole. Held together they reach access for an outside or public principal.
Why it is dangerous
A principal can call s3:PutReplicationConfiguration on the bucket to set up continuous replication to an attacker-owned destination bucket, exfiltrating every current and future object out of band.
In MITRE ATT&CK terms this maps to T1537, Transfer Data to Cloud Account, under the exfiltration tactic. AWS records it in CloudTrail as PutReplicationConfiguration. The call is quiet against normal activity, so it is easy to miss without a rule for it. It also gives an attacker a way to keep access after the first foothold is closed, so it is worth watching even when it looks like routine administration.
Detection
PutReplicationConfigurationPrerequisites
s3:PutReplicationConfiguration, versioning on the source, and iam:PassRole for a role trusting s3.amazonaws.com.
MITRE ATT&CK
T1537 · Transfer Data to Cloud AccountTactic
Exfiltration
A control that would remove it: Restrict s3:PutReplicationConfiguration on the bucket and iam:PassRole for the replication role.
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 s3:PutReplicationConfiguration allow?
Can configure replication to copy a bucket out to an attacker bucket.
What else is needed for s3:PutReplicationConfiguration to be dangerous?
It becomes an escalation only when held together with iam:PassRole. On its own it is not enough, which is what makes the combination easy to miss.
How is exfiltrate through S3 replication detected?
Watch for PutReplicationConfiguration in CloudTrail. The call is quiet against normal activity, so it is easy to miss without a rule for it.
How do you break this path?
A control that would remove it is: Restrict s3:PutReplicationConfiguration on the bucket and iam:PassRole for the replication role. 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?
T1537, Transfer Data to Cloud Account, under the exfiltration tactic.
Related paths
References
Find this in your own account
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