CVE-2023-35928

Nextcloud user scoped external storage can be used to gather credentials of other users

Severity Score

8.8

*CVSS v3.1

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

*Multiple Sources

Exploited in Wild

*KEV

Decision

*SSVC

Descriptions

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.

*Credits: N/A

Attack Vector

Network

Attack Complexity

Low

Privileges Required

Low

User Interaction

None

Scope

Unchanged

Confidentiality

High

Integrity

High

Availability

High

Attack Vector

Network

Attack Complexity

Low

Privileges Required

High

User Interaction

Required

Scope

Changed

Confidentiality

High

Integrity

High

Availability

High

* Common Vulnerability Scoring System

SSVC

Decision:-

Exploitation

Automatable

Tech. Impact

* Organization's Worst-case Scenario

Timeline

2023-06-20 CVE Reserved
2023-06-23 CVE Published
2024-06-29 EPSS Updated
2024-08-02 CVE Updated
---------- Exploited in Wild
---------- KEV Due Date
---------- First Exploit

CWE

CWE-274: Improper Handling of Insufficient Privileges

CAPEC

References (3)

URL	Tag	Source
https://github.com/nextcloud/server/pull/38265	Issue Tracking
https://hackerone.com/reports/1978882	Third Party Advisory

URL	Date	SRC

URL	Date	SRC

URL	Date	SRC
https://github.com/nextcloud/security-advisories/security/advisories/GHSA-637g-xp2c-qh5h	2023-07-05

Affected Vendors, Products, and Versions

Vendor		Product				Version		Other		Status
Vendor	Product	Version	Other	Status	<-- -->	Vendor	Product	Version	Other	Status
Nextcloud Search vendor "Nextcloud"		Nextcloud Server Search vendor "Nextcloud" for product "Nextcloud Server"				>= 19.0.0 < 19.0.13.9 Search vendor "Nextcloud" for product "Nextcloud Server" and version " >= 19.0.0 < 19.0.13.9"		enterprise		Affected
Nextcloud Search vendor "Nextcloud"		Nextcloud Server Search vendor "Nextcloud" for product "Nextcloud Server"				>= 20.0.0 < 20.0.14.14 Search vendor "Nextcloud" for product "Nextcloud Server" and version " >= 20.0.0 < 20.0.14.14"		enterprise		Affected
Nextcloud Search vendor "Nextcloud"		Nextcloud Server Search vendor "Nextcloud" for product "Nextcloud Server"				>= 21.0.0 < 21.0.9.12 Search vendor "Nextcloud" for product "Nextcloud Server" and version " >= 21.0.0 < 21.0.9.12"		enterprise		Affected
Nextcloud Search vendor "Nextcloud"		Nextcloud Server Search vendor "Nextcloud" for product "Nextcloud Server"				>= 22.0.0 < 22.2.10.12 Search vendor "Nextcloud" for product "Nextcloud Server" and version " >= 22.0.0 < 22.2.10.12"		enterprise		Affected
Nextcloud Search vendor "Nextcloud"		Nextcloud Server Search vendor "Nextcloud" for product "Nextcloud Server"				>= 23.0.0 < 23.0.12.7 Search vendor "Nextcloud" for product "Nextcloud Server" and version " >= 23.0.0 < 23.0.12.7"		enterprise		Affected
Nextcloud Search vendor "Nextcloud"		Nextcloud Server Search vendor "Nextcloud" for product "Nextcloud Server"				>= 24.0.0 < 24.0.12.2 Search vendor "Nextcloud" for product "Nextcloud Server" and version " >= 24.0.0 < 24.0.12.2"		enterprise		Affected
Nextcloud Search vendor "Nextcloud"		Nextcloud Server Search vendor "Nextcloud" for product "Nextcloud Server"				>= 25.0.0 < 25.0.7 Search vendor "Nextcloud" for product "Nextcloud Server" and version " >= 25.0.0 < 25.0.7"		-		Affected
Nextcloud Search vendor "Nextcloud"		Nextcloud Server Search vendor "Nextcloud" for product "Nextcloud Server"				>= 25.0.0 < 25.0.7 Search vendor "Nextcloud" for product "Nextcloud Server" and version " >= 25.0.0 < 25.0.7"		enterprise		Affected
Nextcloud Search vendor "Nextcloud"		Nextcloud Server Search vendor "Nextcloud" for product "Nextcloud Server"				>= 26.0.0 < 26.0.2 Search vendor "Nextcloud" for product "Nextcloud Server" and version " >= 26.0.0 < 26.0.2"		-		Affected
Nextcloud Search vendor "Nextcloud"		Nextcloud Server Search vendor "Nextcloud" for product "Nextcloud Server"				>= 26.0.0 < 26.0.2 Search vendor "Nextcloud" for product "Nextcloud Server" and version " >= 26.0.0 < 26.0.2"		enterprise		Affected