// For flags

CVE-2023-35927

Nextcloud system addressbooks can be modified by malicious trusted server

Severity Score

8.1
*CVSS v3.1

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

0
*Multiple Sources

Exploited in Wild

-
*KEV

Decision

-
*SSVC
Descriptions

NextCloud Server and NextCloud Enterprise Server provide file storage for Nextcloud, a self-hosted productivity platform. In NextCloud Server versions 25.0.0 until 25.0.7 and 26.0.0 until 26.0.2 and Nextcloud Enterprise Server versions 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, when two server are registered as trusted servers for each other and successfully exchanged the share secrets, the malicious server could modify or delete VCards in the system addressbook on the origin server. This would impact the available and shown information in certain places, such as the user search and avatar menu. If a manipulated user modifies their own data in the personal settings the entry is fixed again.

Nextcloud Server n 25.0.7 and 26.0.2 and Nextcloud Enterprise Server 21.0.9.12, 22.2.10.12, 23.0.12.7, 24.0.12.2, 25.0.7, and 26.0.2 contain a patch for this issue. A workaround is available. Remove all trusted servers in the "Administration" > "Sharing" settings `…/index.php/settings/admin/sharing`. Afterwards, trigger a recreation of the local system addressbook with the following `occ dav:sync-system-addressbook`.

*Credits: N/A
CVSS Scores
Attack Vector
Network
Attack Complexity
Low
Privileges Required
Low
User Interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
High
Availability
High
Attack Vector
Network
Attack Complexity
Low
Privileges Required
Low
User Interaction
Required
Scope
Changed
Confidentiality
None
Integrity
High
Availability
Low
* 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-284: Improper Access Control
CAPEC
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"
>= 16.0.0 < 19.0.13.9
Search vendor "Nextcloud" for product "Nextcloud Server" and version " >= 16.0.0 < 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