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medium 6.5

CVE-2021-3979 json

A key length flaw was found in Red Hat Ceph Storage.

published 4y ago modified 4mo ago also EUVD-2021-27181

cvss
6.5
version 3.1, NVD
cisa kev
Not listed
not in CISA's catalog
epss
0.6%
EPSS 0.6% chance of exploitation in 30 days, percentile 48%
public exploits
0
none known

Summary

A key length flaw was found in Red Hat Ceph Storage. An attacker can exploit the fact that the key length is incorrectly passed in an encryption algorithm to create a non random key, which is weaker and can be exploited for loss of confidentiality and integrity on encrypted disks.

Patch / fix

  • ceph Debian 14, Debian 13, Debian 12 16.2.9+ds-1

debian advisories DEBIAN-CVE-2021-3979

  • ceph Ubuntu 18.04 LTS 12.2.13-0ubuntu0.18.04.11
  • ceph Ubuntu 20.04 LTS 15.2.17-0ubuntu0.20.04.3

ubuntu advisories UBUNTU-CVE-2021-3979

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • ceph ceph storage 5.1 2:16.2.7-98.el8cp
  • cephadm ceph storage 5.1 2:16.2.7-98.el8cp
  • librbd1 ceph storage 5.1 2:16.2.7-98.el8cp
  • librgw2 ceph storage 5.1 2:16.2.7-98.el8cp
  • rbd-nbd ceph storage 5.1 2:16.2.7-98.el8cp
  • ceph-mds ceph storage 5.1 2:16.2.7-98.el8cp
  • ceph-mgr ceph storage 5.1 2:16.2.7-98.el8cp
  • ceph-mon ceph storage 5.1 2:16.2.7-98.el8cp

red hat advisories RHSA-2022:1174RHSA-2022:1716

  • ceph SLE Module for Basesystem 15 SP3, SLE Micro 5.2, SLE Micro 5.1 +2 more 16.2.9.536+g41a9f9a5573-150300.6.3.1
  • fmt SLE Module for Basesystem 15 SP3, SLE Micro 5.2, SLE Micro 5.1 +2 more 8.0.1-150300.7.5.1
  • ceph-test openSUSE Leap 15.3 16.2.9.536+g41a9f9a5573-150300.6.3.1
  • ceph SLE Module for Basesystem 15 SP4, openSUSE Leap 15.4 16.2.9.536+g41a9f9a5573-150400.3.3.1
  • ceph-test openSUSE Leap 15.4 16.2.9.536+g41a9f9a5573-150400.3.3.1
  • ceph Enterprise Storage 7.1 16.2.9.536+g41a9f9a5573-150300.3.3.1

suse advisories SUSE-SU-2022:4501-1SUSE-SU-2022:2818-1SUSE-SU-2022:2817-1

  • ceph openSUSE Tumbleweed 16.2.9.536+g41a9f9a5573-1.1

opensuse advisories openSUSE-SU-2024:12195-1

Is CVE-2021-3979 in your stack? Fencer shows which of your repositories are affected as soon as an advisory lands, and opens the fix as a pull request.

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Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2021-3979 updated cvss 6.5

ceph: Ceph volume does not honour osd_dmcrypt_key_size

  • Red Hat Ceph Storage 3 ceph, librbd1, librgw2, ceph-mds, ceph-mgr, ceph-mon, +15 more Red Hat Openshift Container Storage 4 ceph
    affected: no fix planned “Out of support scope”
  • Red Hat Openshift Data Foundation 4 ceph Red Hat OpenStack Platform 13 (Queens) librbd1, librgw2, ceph-fuse, librados2, libcephfs2, python-rbd, +6 more
    affected: no fix planned “Will not fix”
  • Red Hat Ceph Storage 4.3 MON ceph 14.2.22-110.el7cp, ceph 14.2.22-110.el8cp, librbd1 14.2.22-110.el7cp, librbd1 14.2.22-110.el8cp, librgw2 14.2.22-110.el7cp, librgw2 14.2.22-110.el8cp, +38 more Red Hat Ceph Storage 4.3 OSD ceph 14.2.22-110.el7cp, ceph 14.2.22-110.el8cp, librbd1 14.2.22-110.el7cp, librbd1 14.2.22-110.el8cp, librgw2 14.2.22-110.el7cp, librgw2 14.2.22-110.el8cp, +26 more Red Hat Ceph Storage 4.3 Tools ceph 14.2.22-110.el7cp, ceph 14.2.22-110.el8cp, librbd1 14.2.22-110.el7cp, librbd1 14.2.22-110.el8cp, librgw2 14.2.22-110.el7cp, librgw2 14.2.22-110.el8cp, +34 more
    fixed: vendor fix RHSA-2022:1716
  • Red Hat Ceph Storage 5.1 MON ceph 16.2.7-98.el8cp, cephadm 16.2.7-98.el8cp, librbd1 16.2.7-98.el8cp, librgw2 16.2.7-98.el8cp, ceph-mgr 16.2.7-98.el8cp, ceph-mon 16.2.7-98.el8cp, +22 more Red Hat Ceph Storage 5.1 OSD ceph 16.2.7-98.el8cp, librbd1 16.2.7-98.el8cp, librgw2 16.2.7-98.el8cp, ceph-osd 16.2.7-98.el8cp, ceph-base 16.2.7-98.el8cp, ceph-test 16.2.7-98.el8cp, +12 more Red Hat Ceph Storage 5.1 Tools ceph 16.2.7-98.el8cp, cephadm 16.2.7-98.el8cp, librbd1 16.2.7-98.el8cp, librgw2 16.2.7-98.el8cp, rbd-nbd 16.2.7-98.el8cp, ceph-mds 16.2.7-98.el8cp, +20 more
    fixed: vendor fix RHSA-2022:1174
  • Red Hat Ceph Storage 4.3 MON python-rsa 4.8-1.el8cp, python3-rsa 4.8-1.el8cp Red Hat Ceph Storage 4.3 Tools libtcmu 1.5.2-5.el7cp, libtcmu 1.5.2-5.el8cp, ceph-iscsi 3.4-5.el7cp, ceph-iscsi 3.4-5.el8cp, libntirpc 3.4-1.1.el7cp, libntirpc 3.4-1.1.el8cp, +20 more Red Hat Ceph Storage 5.1 MON python-rsa 4.8-1.el8cp, python3-rsa 4.8-1.el8cp Red Hat Ceph Storage 5.1 Tools libtcmu 1.5.4-4.el8cp, ceph-iscsi 3.5-2.el8cp, tcmu-runner 1.5.4-4.el8cp, ceph-ansible 6.0.25.4-1.el8cp, cephadm-ansible 0.1-4.g6754c10.el8cp Red Hat Enterprise Linux 7 librbd1, librados2, python-rbd, ceph-common, python-rados Red Hat Enterprise Linux 8 librbd1, librados2, libcephfs2, libradosstriper1
    +1 more products
    Red Hat Enterprise Linux 9 librbd1, librados2
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

0.60% chance of exploitation in the next 30 days, higher than 48% of all scored CVEs (FIRST EPSS, 2026-11-09).

CVSS scores

assigned by version score vector
NVD 3.1 6.5 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N

Affected products

  • n/a ceph

Classification

Weakness
  • CWE-327 Use of a Broken or Risky Cryptographic Algorithm
  • CWE-287 Improper Authentication

References

Sources

Fencer Intel keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.