How severe is CVE-2021-20288?

CVE-2021-20288 has a CVSS 3.x base score of 7.2, rated high severity. It is exploitable over network with low attack complexity, requires high privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.

Is CVE-2021-20288 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (81st percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-20288?

CVE-2021-20288 primarily affects Redhat Ceph Storage. In total, 6 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-20288?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.

When was CVE-2021-20288 published?

CVE-2021-20288 was published on 2021-04-15 and last updated on 2026-06-17.

CVE-2021-20288

CVE-2021-20288 is a high-severity vulnerability in Redhat Ceph Storage with a CVSS 3.x base score of 7.2. It is not currently listed as actively exploited by CISA, and its EPSS exploit-prediction score is low. The underlying weakness is classified as CWE-287.

Key facts

Severity: High (CVSS 3.x base score 7.2)
CVSS v2: 6.5
EPSS exploit prediction: 2% (81st percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-287
Affected product: Redhat Ceph Storage
Published: 2021-04-15
Last modified: 2026-06-17

Description

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.

Frequently asked questions

What is CVE-2021-20288?: 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.
How severe is CVE-2021-20288?: CVE-2021-20288 has a CVSS 3.x base score of 7.2, rated high severity. It is exploitable over network with low attack complexity, requires high privileges and no user interaction. Impact on confidentiality is high, integrity high, and availability high.
Is CVE-2021-20288 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (81st percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-20288?: CVE-2021-20288 primarily affects Redhat Ceph Storage. In total, 6 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-20288?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround. Given its high severity, prioritise patching exposed systems.
When was CVE-2021-20288 published?: CVE-2021-20288 was published on 2021-04-15 and last updated on 2026-06-17.

References

Affected products (6)

cpe:2.3:a:linuxfoundation:ceph:*:*:*:*:*:*:*:*
cpe:2.3:a:redhat:ceph_storage:4.0:*:*:*:*:*:*:*
cpe:2.3:o:fedoraproject:fedora:32:*:*:*:*:*:*:*
cpe:2.3:o:fedoraproject:fedora:33:*:*:*:*:*:*:*
cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:*
cpe:2.3:o:debian:debian_linux:10.0:*:*:*:*:*:*:*

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