How severe is CVE-2021-20281?

CVE-2021-20281 has a CVSS 3.x base score of 5.3, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is low, integrity none, and availability none.

Is CVE-2021-20281 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (67th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-20281?

CVE-2021-20281 primarily affects Moodle. In total, 3 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.

How do I fix CVE-2021-20281?

Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.

When was CVE-2021-20281 published?

CVE-2021-20281 was published on 2021-03-15 and last updated on 2026-06-17.

CVE-2021-20281

CVE-2021-20281 is a medium-severity vulnerability in Moodle with a CVSS 3.x base score of 5.3. 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-863.

Key facts

Severity: Medium (CVSS 3.x base score 5.3)
CVSS v2: 5.0
EPSS exploit prediction: 1% (67th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-863
Affected product: Moodle
Published: 2021-03-15
Last modified: 2026-06-17

Description

It was possible for some users without permission to view other users' full names to do so via the online users block in moodle before 3.10.2, 3.9.5, 3.8.8, 3.5.17.

Frequently asked questions

What is CVE-2021-20281?: It was possible for some users without permission to view other users' full names to do so via the online users block in moodle before 3.10.2, 3.9.5, 3.8.8, 3.5.17.
How severe is CVE-2021-20281?: CVE-2021-20281 has a CVSS 3.x base score of 5.3, rated medium severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is low, integrity none, and availability none.
Is CVE-2021-20281 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 1% (67th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-20281?: CVE-2021-20281 primarily affects Moodle. In total, 3 product configurations (CPEs) are listed as vulnerable; see the affected-products list for the exact versions.
How do I fix CVE-2021-20281?: Review the linked vendor and NVD advisories for patched versions and mitigations, then upgrade or apply the recommended workaround.
When was CVE-2021-20281 published?: CVE-2021-20281 was published on 2021-03-15 and last updated on 2026-06-17.

References

Affected products (3)

cpe:2.3:a:moodle:moodle:*:*:*:*:*:*:*:*
cpe:2.3:o:fedoraproject:fedora:32:*:*:*:*:*:*:*
cpe:2.3:o:fedoraproject:fedora:34:*:*:*:*:*:*:*

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