CVE-2023-35928

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

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.

Category

8.4
CVSS
Severity: High
CVSS 3.1 •
EPSS 0.33%
Vendor Advisory github.com
Affected: nextcloud security-advisories
Published at:
Updated at:

References

Link Tags
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

Frequently Asked Questions

What is the severity of CVE-2023-35928?
CVE-2023-35928 has been scored as a high severity vulnerability.
How to fix CVE-2023-35928?
To fix CVE-2023-35928, make sure you are using an up-to-date version of the affected component(s) by checking the vendor release notes. As for now, there are no other specific guidelines available.
Is CVE-2023-35928 being actively exploited in the wild?
As for now, there are no information to confirm that CVE-2023-35928 is being actively exploited. According to its EPSS score, there is a ~0% probability that this vulnerability will be exploited by malicious actors in the next 30 days.
What software or system is affected by CVE-2023-35928?
CVE-2023-35928 affects nextcloud security-advisories.
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