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العربيةDisable S3 Block Public Access
Can disable Block Public Access, enabling a public policy or ACL to take effect.
Grants escalation on its own.
s3:PutBucketPublicAccessBlockOn its own, s3:PutBucketPublicAccessBlock can disable Block Public Access, enabling a public policy or ACL to take effect. On a wide resource scope that alone reaches access for an outside or public principal.
Why it is dangerous
A principal can call s3:PutBucketPublicAccessBlock on the bucket to turn off Block Public Access, so a public bucket policy or ACL grant is no longer overridden and actually exposes the data.
In MITRE ATT&CK terms this maps to T1562, Impair Defenses, under the defense evasion tactic. AWS records it in CloudTrail as PutBucketPublicAccessBlock, PutAccountPublicAccessBlock. The call shows up in CloudTrail but blends into normal administration, so it needs a rule to stand out.
Detection
PutBucketPublicAccessBlockPutAccountPublicAccessBlockPrerequisites
s3:PutBucketPublicAccessBlock on the bucket (or account-level PutAccountPublicAccessBlock).
MITRE ATT&CK
T1562 · Impair DefensesTactic
Defense Evasion
A control that would remove it: Remove s3:PutBucketPublicAccessBlock / PutAccountPublicAccessBlock from the principal; keep account-level BPA on and deny changes via SCP.
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:PutBucketPublicAccessBlock allow?
Can disable Block Public Access, enabling a public policy or ACL to take effect.
Can s3:PutBucketPublicAccessBlock escalate privileges on its own?
Yes. Held on a broad enough resource it reaches access for an outside or public principal with no other permission.
How is disable S3 Block Public Access detected?
Watch for PutBucketPublicAccessBlock, PutAccountPublicAccessBlock 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: Remove s3:PutBucketPublicAccessBlock / PutAccountPublicAccessBlock from the principal; keep account-level BPA on and deny changes via SCP. 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?
T1562, Impair Defenses, under the defense evasion tactic.
Related paths
References
Find this in your own account
We run a read-only scan of one AWS account and show you which of these paths exist, ranked by blast radius, with the change that breaks each one. First validated paths within the hour.