8.8
HIGH
CVE-2023-35928
Nextcloud Server File External Storage Privilege Escalation Vulnerability
Description

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 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.

INFO

Published Date :

June 23, 2023, 9:15 p.m.

Last Modified :

July 5, 2023, 1:30 p.m.

Remotely Exploitable :

Yes !

Impact Score :

5.9

Exploitability Score :

2.8
Affected Products

The following products are affected by CVE-2023-35928 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 Nextcloud nextcloud_server
2 Nextcloud notes
References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2023-35928.

URL Resource
https://github.com/nextcloud/security-advisories/security/advisories/GHSA-637g-xp2c-qh5h Vendor Advisory
https://github.com/nextcloud/server/pull/38265 Issue Tracking
https://hackerone.com/reports/1978882 Third Party Advisory

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2023-35928 vulnerability anywhere in the article.

The following table lists the changes that have been made to the CVE-2023-35928 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • CVE Modified by [email protected]

    May. 14, 2024

    Action Type Old Value New Value
  • Initial Analysis by [email protected]

    Jul. 05, 2023

    Action Type Old Value New Value
    Added CVSS V3.1 NIST AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
    Changed Reference Type https://github.com/nextcloud/security-advisories/security/advisories/GHSA-637g-xp2c-qh5h No Types Assigned https://github.com/nextcloud/security-advisories/security/advisories/GHSA-637g-xp2c-qh5h Vendor Advisory
    Changed Reference Type https://github.com/nextcloud/server/pull/38265 No Types Assigned https://github.com/nextcloud/server/pull/38265 Issue Tracking
    Changed Reference Type https://hackerone.com/reports/1978882 No Types Assigned https://hackerone.com/reports/1978882 Third Party Advisory
    Added CWE NIST NVD-CWE-noinfo
    Added CPE Configuration OR *cpe:2.3:a:nextcloud:nextcloud_server:*:*:*:*:enterprise:*:*:* versions from (including) 19.0.0 up to (excluding) 19.0.13.9 *cpe:2.3:a:nextcloud:nextcloud_server:*:*:*:*:enterprise:*:*:* versions from (including) 20.0.0 up to (excluding) 20.0.14.14 *cpe:2.3:a:nextcloud:nextcloud_server:*:*:*:*:enterprise:*:*:* versions from (including) 21.0.0 up to (excluding) 21.0.9.12 *cpe:2.3:a:nextcloud:nextcloud_server:*:*:*:*:enterprise:*:*:* versions from (including) 22.0.0 up to (excluding) 22.2.10.12 *cpe:2.3:a:nextcloud:nextcloud_server:*:*:*:*:enterprise:*:*:* versions from (including) 23.0.0 up to (excluding) 23.0.12.7 *cpe:2.3:a:nextcloud:nextcloud_server:*:*:*:*:enterprise:*:*:* versions from (including) 24.0.0 up to (excluding) 24.0.12.2 *cpe:2.3:a:nextcloud:nextcloud_server:*:*:*:*:-:*:*:* versions from (including) 25.0.0 up to (excluding) 25.0.7 *cpe:2.3:a:nextcloud:nextcloud_server:*:*:*:*:enterprise:*:*:* versions from (including) 25.0.0 up to (excluding) 25.0.7 *cpe:2.3:a:nextcloud:nextcloud_server:*:*:*:*:-:*:*:* versions from (including) 26.0.0 up to (excluding) 26.0.2 *cpe:2.3:a:nextcloud:nextcloud_server:*:*:*:*:enterprise:*:*:* versions from (including) 26.0.0 up to (excluding) 26.0.2
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2023-35928 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2023-35928 weaknesses.

Exploit Prediction

EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days.

0.24 }} 0.14%

score

0.64558

percentile

CVSS31 - Vulnerability Scoring System
Attack Vector
Attack Complexity
Privileges Required
User Interaction
Scope
Confidentiality
Integrity
Availability