Is CVE-2021-22915 in the CISA KEV catalog?

No. CVE-2021-22915 is not currently on the CISA Known Exploited Vulnerabilities list.

What is the CVSS severity of CVE-2021-22915?

CVE-2021-22915 has a CVSS v3 base score of 9.8 (CRITICAL).

What is the EPSS score for CVE-2021-22915?

CVE-2021-22915 has an EPSS score of 1.74% (75th percentile), estimating the probability of exploitation in the next 30 days.

How do I fix CVE-2021-22915?

Upgrade nextcloud server to 21.0.2 or later.

CVE & CISA-KEV Catalog

CVE-2021-22915

CRITICALEPSS 75th pctl

9.8

CVSS v3

NVD

Description

Nextcloud server before 19.0.11, 20.0.10, 21.0.2 is vulnerable to brute force attacks due to lack of inclusion of IPv6 subnets in rate-limiting considerations. This could potentially result in an attacker bypassing rate-limit controls such as the Nextcloud brute-force protection.

CWE-307

How to fix

Remediation Available

nextcloud serverNVD

Affected:>= 21.0.0, < 21.0.2Fixed in:21.0.2CVE-2021-22915derived from NVD

Remediation is compiled from vendor and distribution security advisories. Always confirm against the linked source for your exact version and platform.

CVSS v3 Vector

Exploitability

Attack VectorNetwork

Attack ComplexityLow

Privileges RequiredNone

User InteractionNone

ScopeUnchanged

Impact

ConfidentialityHigh

IntegrityHigh

AvailabilityHigh

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

Exploit Intelligence

1.74%probability of exploitation in 30 days

75thpercentile

Elevated risk: more likely to be exploited than 75% of all known CVEs.

References

Third-Party Advisory1

hackerone.com

Other references3

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This product uses NVD data but is not endorsed or certified by the NVD. EPSS scores courtesy of FIRST.org (https://www.first.org/epss). Source: CISA KEV Catalog. Data as of 2024-11-21.