Published: 15 April 2021
An authentication flaw was found in ceph in versions before 14.2.20. When the monitor handles CEPHX_GET_AUTH_SESSION_KEY requests, it doesn't sanitize other_keys, allowing key reuse. An attacker who can request a global_id can exploit the ability of any user to request a global_id previously associated with another user, as ceph does not force the reuse of old keys to generate new ones. The highest threat from this vulnerability is to data confidentiality and integrity as well as system availability.
From the Ubuntu security team
It was discovered that Ceph contained an authentication flaw, leading to key reuse. An attacker could use this to cause a denial of service or possibly impersonate another user.
CVSS 3 base score: 7.2
Launchpad, Ubuntu, Debian
|Ubuntu 21.04 (Hirsute Hippo)||
|Ubuntu 20.04 LTS (Focal Fossa)||
|Ubuntu 18.04 LTS (Bionic Beaver)||
|Ubuntu 16.04 ESM (Xenial Xerus)||
|Ubuntu 14.04 ESM (Trusty Tahr)||
Upstream: https://github.com/ceph/ceph/commit/059eabcc0ada81078a898cdc25cf72bf3d506ad0 (nautilus)
Upstream: https://github.com/ceph/ceph/commit/05b3b6a305ddbb56cc53bbeadf5866db4d785f49 (nautilus)
we will not be backporting this fix to Ubuntu 18.04 LTS and earlier. this is fixed in 16.2.1 in hirsute-updates but has not been pushed to the security pocket