How severe is CVE-2021-37628?

CVE-2021-37628 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.

Is CVE-2021-37628 being actively exploited?

It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (79th percentile), an estimate of the probability of exploitation in the next 30 days.

What products are affected by CVE-2021-37628?

CVE-2021-37628 affects Nextcloud Richdocuments. See the affected-products list for the exact vulnerable versions.

How do I fix CVE-2021-37628?

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-2021-37628 published?

CVE-2021-37628 was published on 2021-09-07 and last updated on 2026-06-17.

CVE-2021-37628

CVE-2021-37628 is a high-severity vulnerability in Nextcloud Richdocuments with a CVSS 3.x base score of 7.5. 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-639.

Key facts

Severity: High (CVSS 3.x base score 7.5)
CVSS v2: 5.0
EPSS exploit prediction: 2% (79th percentile)
Actively exploited: Not listed in CISA KEV
Weakness: CWE-639
Affected product: Nextcloud Richdocuments
Published: 2021-09-07
Last modified: 2026-06-17

Description

Nextcloud Richdocuments is an open source collaborative office suite. In affected versions the File Drop features ("Upload Only" public link shares in Nextcloud) can be bypassed using the Nextcloud Richdocuments app. An attacker was able to read arbitrary files in such a share. It is recommended that the Nextcloud Richdocuments is upgraded to 3.8.4 or 4.2.1. If upgrading is not possible then it is recommended to disable the Richdocuments application.

Frequently asked questions

What is CVE-2021-37628?: Nextcloud Richdocuments is an open source collaborative office suite. In affected versions the File Drop features ("Upload Only" public link shares in Nextcloud) can be bypassed using the Nextcloud Richdocuments app. An attacker was able to read arbitrary files in such a share. It is recommended that the Nextcloud Richdocuments is upgraded to 3.8.4 or 4.2.1. If upgrading is not possible then it is recommended to disable the Richdocuments application.
How severe is CVE-2021-37628?: CVE-2021-37628 has a CVSS 3.x base score of 7.5, rated high severity. It is exploitable over network with low attack complexity, requires no privileges and no user interaction. Impact on confidentiality is high, integrity none, and availability none.
Is CVE-2021-37628 being actively exploited?: It is not currently listed in CISA's KEV catalog. Its EPSS exploit-prediction score is 2% (79th percentile), an estimate of the probability of exploitation in the next 30 days.
What products are affected by CVE-2021-37628?: CVE-2021-37628 affects Nextcloud Richdocuments. See the affected-products list for the exact vulnerable versions.
How do I fix CVE-2021-37628?: 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-2021-37628 published?: CVE-2021-37628 was published on 2021-09-07 and last updated on 2026-06-17.

References

Affected products (1)

cpe:2.3:a:nextcloud:richdocuments:*:*:*:*:*:*:*:*

More vulnerabilities in Nextcloud Richdocuments

CVE-2022-31024 — Medium (CVSS 6.5): richdocuments is the repository for NextCloud Collabra, the app for Nextcloud Office collaboration. Prior to versions…
CVE-2023-25150 — Medium (CVSS 5.8): Nextcloud office/richdocuments is an office suit for the nextcloud server platform. In affected versions the Collabora…
CVE-2023-28645 — Medium (CVSS 5.7): Nextcloud richdocuments is a Nextcloud app integrating the office suit Collabora Online. In affected versions the…
CVE-2021-37629 — Medium (CVSS 5.3): Nextcloud Richdocuments is an open source collaborative office suite. In affected versions there is a lack of rate…
CVE-2021-39223 — Medium (CVSS 4.8): Nextcloud is an open-source, self-hosted productivity platform. The Nextcloud Richdocuments application prior to…
CVE-2021-32748 — Medium (CVSS 4.3): Nextcloud Richdocuments in an open source self hosted online office. Nextcloud uses the WOPI ("Web Application Open…

All CVEs affecting Nextcloud Richdocuments →

Other CWE-639 (Authorization Bypass Through User-Controlled Key (IDOR)) vulnerabilities

CVE-2025-40805 — Critical (CVSS 10.0): Affected devices do not properly enforce user authentication on specific API endpoints. This could facilitate an…
CVE-2024-45032 — Critical (CVSS 10.0): A vulnerability has been identified in Industrial Edge Management Pro (All versions < V1.9.5), Industrial Edge…
CVE-2026-34037 — Critical (CVSS 9.9): Coolify is an open-source and self-hostable tool for managing servers, applications, and databases. Prior to…
CVE-2026-52782 — Critical (CVSS 9.9): OpenProject is open-source, web-based project management software. Prior to 17.3.3 and 17.4.1, there is an IDOR through…
CVE-2026-45552 — Critical (CVSS 9.9): Roxy-WI is a web interface for managing Haproxy, Nginx, Apache and Keepalived servers. In versions 8.2.6.4 and prior,…
CVE-2026-29200 — Critical (CVSS 9.9): A critical IDOR vulnerability has been discovered in Comet Backup affecting all versions from 20.11.0 to 26.1.1 and…

Browse all CWE-639 (Authorization Bypass Through User-Controlled Key (IDOR)) vulnerabilities →