Cyber Resilience

CVE-2021-32654

High

Published: 01 June 2021

Published
01 June 2021
Modified
21 November 2024
KEV Added
—
Patch
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CVSS Score v3.1 8.1 CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:H/A:H
EPSS Score 0.0027 51.2th percentile
Risk Priority 16 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2021-32654 is a high-severity Authorization Bypass Through User-Controlled Key (CWE-639) vulnerability in Nextcloud Nextcloud Server. Its CVSS base score is 8.1 (High).

Operationally, ranked in the top 48.8% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.

EU & UK References

Vulnerability details

Nextcloud Server is a Nextcloud package that handles data storage. In versions prior to 19.0.11, 20.0.10, and 21.0.2, an attacker is able to receive write/read privileges on any Federated File Share. Since public links can be added as federated file…

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share, this can also be exploited on any public link. Users can upgrade to patched versions (19.0.11, 20.0.10 or 21.0.2) or, as a workaround, disable federated file sharing.

CWE(s)
CWE-639

Related Threats

No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.

Affected Assets

nextcloud
nextcloud server
≤ 19.0.11 · 20.0.0 — 20.0.10 · 21.0.0 — 21.0.2

Mitigating Controls

Likely Mitigating Controls AI

Per-CVE control mapping for this CVE has not run yet; the list below is derived from the weakness types (CWEs) cited in the NVD entry.

AC-24 Access Control Decisions
addresses: CWE-639

Per-request decision making makes it harder to bypass authorization using user-controlled keys without proper validation in the decision process.

AC-3 Access Enforcement
addresses: CWE-639

Consistent enforcement of approved authorizations makes bypassing via user-controlled keys ineffective.

References