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Vulnerability · Published Jun 23, 2023 · Assigned by GitHub_M

CVE-2023-35928Nextcloud user scoped external storage can be used to gather credentials of other users

High 8.5

In plain English

A high-severity security flaw in security-advisories from nextcloud. There are no confirmed reports of exploitation so far. The chance it is exploited in the next 30 days is estimated at 1.0% (higher than 62% of all known vulnerabilities).

Severity (CVSS 3.1)8.5High
Exploit odds (30 days)1.0%top 37.6% of all CVEs
Exploited in the wildNo reportsCISA SSVC: none
Attack toolingNoneno public tooling known

Official 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.

Affected products (as reported)

VendorProductVersions
nextcloud security-advisories Nextcloud Enterprise Server >= 19.0.0, < 19.0.13.9Nextcloud Enterprise Server >= 20.0.0.0, < 20.0.14.14Nextcloud Enterprise Server >= 21.0.0.0, < 21.0.9.12Nextcloud Enterprise Server >= 22.0.0.0, < 22.2.10.12Nextcloud Enterprise Server >= 23.0.0.0, < 23.0.12.7Nextcloud Enterprise Server >= 24.0.0.0, < 24.0.12.2Nextcloud Enterprise Server >= 25.0.0, < 25.0.7 Nextcloud Enterprise Server >= 26.0.0, < 26.0.2

Weakness: CWE-274 · Vector: CVSS:3.1/AV:N/AC:L/PR:H/UI:R/S:C/C:H/I:H/A:H

References