CVE-2023-35927
HighCVSS 7.6Exploitation Probability (EPSS)
Low risk46th percentile - higher than 46% of all known CVEs
Summary
NextCloud Server and NextCloud Enterprise Server have a vulnerability that allows a malicious server to modify or delete VCards in the system address book when two servers are registered as trusted and exchange share secrets. This affects versions from 25.0.0 to 25.0.7 and from 26.0.0 to 26.0.2, as well as various versions of Nextcloud Enterprise Server.
Risk Assessment
The risk involves the potential manipulation of user data, which can lead to incorrect information in the system and loss of trust in the platform. Users may be unaware that their data has been altered.
Recommendation
It is recommended to remove all trusted servers in the administration settings and recreate the local address book using the command `occ dav:sync-system-addressbook`. Additionally, update to a version that contains the patch.
Other vulnerabilities in NextCloud Server, NextCloud Enterprise Server
See all- CVE-2023-35928High
In Nextcloud Server versions 25.0.0 to 25.0.7 and 26.0.0 to 26.0.2, as well as in Nextcloud Enterprise Server versions 19.0.0 to 19.0.13.9, there was a vulnerability that allowed users to access another user's login credentials and take over their account. This issue has been patched in newer versions of the software.
- CVE-2023-35172High
NextCloud Server and NextCloud Enterprise Server have a vulnerability that allows an attacker to bruteforce password reset links in specific versions of the software. This affects versions 25.0.0 to 25.0.7 and 26.0.0 to 26.0.2 for NextCloud Server and various versions of NextCloud Enterprise Server.
- CVE-2023-35171Medium
NextCloud Server and NextCloud Enterprise Server provide file storage for a productivity platform. In versions 26.0.0 to 26.0.2, an attacker could supply a URL that redirects an unsuspecting user from a legitimate domain to an attacker's site.
Original NVD description (English source)
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`.