High severity · published Jun 23, 2023
CVE-2023-35928
Nextcloud Server is a space for data storage on Nextcloud, a self-hosted productivity playform
8.8
CVSS
1%
EPSS
No
On KEV
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.
CVSS vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H
Attack vector
Network
Complexity
Low
Privileges
Low
User interaction
None
Confidentiality
High
Integrity
High
Availability
High
Scope
Unchanged
Exploitation
Is it being used?
Exploit prediction (EPSS)1.0% · higher than 62% of CVEs
Exploited in the wildNo evidence yet
CISA KEVNot listed
Ransomware campaign useNot known
Affected products
Which versions
NS
Nextcloud Server · Nextcloud
19.0.0 before 19.0.13.9; 20.0.0 before 20.0.14.14; 21.0.0 before 21.0.9.12; 22.0.0 before 22.2.10.12; 23.0.0 before 23.0.12.7; 24.0.0 before 24.0.12.2; +4 more · source: NVD
References
NVD
https://nvd.nist.gov/vuln/detail/CVE-2023-35928
CVE.org
https://www.cve.org/CVERecord?id=CVE-2023-35928
Vendor Advisory
https://github.com/nextcloud/security-advisories/security/advisories/GHSA-637g-xp2c-qh5h
Issue Tracking
https://github.com/nextcloud/server/pull/38265
Third Party Advisory
https://hackerone.com/reports/1978882
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