CVE-2021-20288

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.

Notes

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

Status

Severity score breakdown

References

• https://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2021-20288
• https://www.openwall.com/lists/oss-security/2021/04/14/2
• https://docs.ceph.com/en/latest/security/CVE-2021-20288/#cve-2021-20288
• https://ubuntu.com/security/notices/USN-4998-1
• https://ubuntu.com/security/notices/USN-5128-1
• NVD
• Launchpad
• Debian

Bugs

• http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=986974