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GitHub_MCVELIST:CVE-2023-35927

HistoryJun 23, 2023 - 8:53 p.m.

CVE-2023-35927 Nextcloud system addressbooks can be modified by malicious trusted server

2023-06-2320:53:33

CWE-284

GitHub_M

www.cve.org

nextcloud

server

vulnerability

addressbook

modification

trusted servers

vcards

CVSS3

7.6

Attack Vector

NETWORK

Attack Complexity

LOW

Privileges Required

LOW

User Interaction

REQUIRED

Scope

CHANGED

Confidentiality Impact

NONE

Integrity Impact

HIGH

Availability Impact

LOW

CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:C/C:N/I:H/A:L

AI Score

Confidence

High

EPSS

0.001

Percentile

49.7%

JSON

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.

CNA Affected

[
  {
    "vendor": "nextcloud",
    "product": "security-advisories",
    "versions": [
      {
        "version": "Nextcloud Server >= 25.0.0, < 25.0.7",
        "status": "affected"
      },
      {
        "version": "Nextcloud Server >= 26.0.0, < 26.0.2",
        "status": "affected"
      },
      {
        "version": "Nextcloud Enterprise Server >= 25.0.0, < 25.0.7",
        "status": "affected"
      },
      {
        "version": "Nextcloud Enterprise Server >= 26.0.0, < 26.0.2",
        "status": "affected"
      },
      {
        "version": "Nextcloud Enterprise Server >= 21.0.0, < 21.0.9.12",
        "status": "affected"
      },
      {
        "version": "Nextcloud Enterprise Server >= 22.0.0, < 22.2.10.12",
        "status": "affected"
      },
      {
        "version": "Nextcloud Enterprise Server >= 23.0.0, < 23.0.12.7",
        "status": "affected"
      },
      {
        "version": "Nextcloud Enterprise Server >= 24.0.0, < 24.0.12.2",
        "status": "affected"
      }
    ]
  }
]

References

github.com/nextcloud/security-advisories/security/advisories/GHSA-h7f7-535f-7q87

github.com/nextcloud/server/pull/38247

hackerone.com/reports/1976754