CVE-2023-43040 Ceph: Improperly verified POST keys.

["Sage [They / Them] McTaggart" <amctagga () redhat com>]

Hello all,
A flaw was found in Ceph RGW. An unprivileged user can write to any
bucket(s) accessible by a given key if a POST's form-data contains a key
called 'bucket' with a value matching the name of the bucket used to sign
the request.

The result of this is that a user could actually upload to any bucket
accessible by the specified access key as long as the bucket in the POST
policy matches the bucket in said POST form part.

We have assigned it a CVE of CVE-2023-43040 and the patch is attached.

Credits to Lucas Henry of Digital Ocean.

Sage McTaggart
IBM Product Security

amct () redhat com

sagemct () ibm com


Pronouns:They/Them/Theirs

Attachment: rgw.patch
Description: