#VU53692 Improper Authentication in Ceph - CVE-2021-20288

Vulnerability identifier: #VU53692

Vulnerability risk: Medium

CVSSv4.0: 6.1 [CVSS:4.0/AV:N/AC:L/AT:N/PR:H/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2021-20288

CWE-ID: CWE-287

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Ceph
Server applications / Other server solutions

Vendor: Red Hat Inc.

Description

The vulnerability allows a remote attacker to bypass authentication process.

The vulnerability exists due to an error in authentication flow related to CEPHX_GET_AUTH_SESSION_KEY requests. The application does not check other_keys and allows key reuse. A remote 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.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Ceph: 14.0.0 - 16.2.0

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External links
https://bugzilla.redhat.com/show_bug.cgi?id=1938031
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/362CEPPYF3YMJZBEJQUT3KDE2EHYYIYQ/
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/5BPIAYTRCWAU4XWCDBK2THEFVXSC4XGK/
https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/JVWUKUUS5BCIFWRV3JCUQMAPJ4HIWSED/
https://security.gentoo.org/glsa/202105-39

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Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote authenticated privileged user via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.