Cyber Resilience

CVE-2023-35928

Nextcloud Server 19.0.0 – 19.0.13.9

Published
23 June 2023
Modified
21 November 2024
Patch / advisory
CVSS Score v3.1 8.4
Click a component to see what it means
Raw vectorCVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:H/I:H/A:H
EPSS Score 0.0098 59th percentile
Risk Priority 57 floored blend · peak EPSS

Summary

CVE-2023-35928 is a high-severity Improper Handling of Insufficient Privileges (CWE-274) vulnerability in Nextcloud Nextcloud Server. Its CVSS base score is 8.4 (High).

Operationally, exploitation aligns with the MITRE ATT&CK technique Exploitation for Privilege Escalation (T1068); ranked in the top 41% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog.

OWASP Top 10 for Web (2025)

EU & UK References

Vulnerability Data

Nextcloud Server is a space for data storage on Nextcloud, a self-hosted productivity playform. In NextCloud Server versions 25.0.0 until 25.0.7 and 26.0.0 until 26.0.2 and Nextcloud Enterprise Server versions 19.0.0 until 19.0.13.9, 20.0.0 until 20.0.14.14, 21.0.0 until 21.0.9.12, 22.0.0…

more

until 22.2.10.12, 23.0.0 until 23.0.12.7, 24.0.0 until 24.0.12.2, 25.0.0 until 25.0.7, and 26.0.0 until 26.0.2, a user could use this functionality to get access to the login credentials of another user and take over their account. This issue has been patched in Nextcloud Server versions 25.0.7 and 26.0.2 and NextCloud Enterprise Server versions 19.0.13.9, 20.0.14.14, 21.0.9.12, 22.2.10.12, 23.0.12.7, 24.0.12.2, 25.0.7, and 26.0.2. Three workarounds are available. Disable app files_external. Change config setting "Allow users to mount external storage" to disabled in "Administration" > "External storage" settings `…/index.php/settings/admin/externalstorages`. Change config setting to disallow users to create external storages in "Administration" > "External storage" settings `…/index.php/settings/admin/externalstorages` with the types FTP, Nextcloud, SFTP, and/or WebDAV.

CWE(s)

Related Threats

MITRE ATT&CK Enterprise Techniques

T1068 Exploitation for Privilege Escalation Privilege Escalation
Adversaries may exploit software vulnerabilities in an attempt to elevate privileges.
T1548 Abuse Elevation Control Mechanism Privilege Escalation
Adversaries may circumvent mechanisms designed to control privilege elevation to gain higher-level permissions.
Derived from this CVE’s CWE(s) via the direct CWE→ATT&CK cross-walk.

CVEs Like This One

CVE-2026-45285Same product: Nextcloud Nextcloud Server
CVE-2024-52516Same product: Nextcloud Nextcloud Server
CVE-2024-52518Same product: Nextcloud Nextcloud Server
CVE-2026-45690Same product: Nextcloud Nextcloud Server
CVE-2026-45283Same product: Nextcloud Nextcloud Server
CVE-2026-45691Same product: Nextcloud Nextcloud Server
CVE-2024-37313Same product: Nextcloud Nextcloud Server
CVE-2025-47790Same product: Nextcloud Nextcloud Server
CVE-2024-37315Same product: Nextcloud Nextcloud Server
CVE-2023-39962Same product: Nextcloud Nextcloud Server

Affected Assets

nextcloud
nextcloud server
19.0.0 — 19.0.13.9 · 20.0.0 — 20.0.14.14 · 21.0.0 — 21.0.9.12

Mitigating Controls

Control response

Prevent
Stop it (NIST 800-53)

Detect
Catch it (NIST detect / respond)

Harden
Shrink the surface (DISA STIG)
  • 5 hardening rules · 3 OS baselines
Validate
Prove the fix (OWASP ASVS)

Mitigating Controls (NIST CSF 2.0) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→CSF cross-walk (authority under review) — links open the control.

PR.AA-05 mostly match
prevents

Enforcing least-privilege access policies directly prevents improper handling of insufficient privileges.

Mitigating Controls (ISO/IEC 27001:2022 Annex A) AI

Derived directly from the weakness types (CWEs) cited in the NVD entry via our AI-authored CWE→ISO cross-walk (authority under review) — links open the control.

prevents

Privileged-access-rights control directly limits the situations in which insufficient privileges can occur.

prevents

Information-access-restriction mechanisms enforce least-privilege checks that mitigate the weakness at runtime.

prevents

Access control policy defines privilege boundaries but does not guarantee correct runtime handling when privileges prove insufficient.

prevents

Access-rights provisioning and review reduce privilege gaps, yet do not address the software’s failure to handle insufficient privileges gracefully.

mitigates

Restricting privileged utilities reduces exposure but does not address how the application handles privilege shortfalls.

prevents

Secure SDLC practices can include privilege checks, yet the control itself does not mandate handling of insufficient privileges.

Hardening callouts derived

Configuration rules from DISA STIG baselines that bear on weaknesses of the type cited by this CVE. Each rule is shown with the relationship its mapping actually records, against the CWE it was authored against. Derived via CVE→CWE over `controls_xwalks` (authoritative rows only; rows rated `none` are excluded).

Oracle Linux 9 (2 rules)
  • V-271452 OL 9 must use a Linux Security Module configured to enforce limits on system services. prevents CWE-274
  • V-271640 OL 9 must be configured so that the Network File System (NFS) is configured to use RPCSEC_GSS. prevents CWE-274
RHEL 9 (1 rule)
  • V-258078 RHEL 9 must use a Linux Security Module configured to enforce limits on system services. prevents CWE-274

References