// For flags

CVE-2021-32656

Trusted servers exchange can be triggered by attacker

Severity Score

8.6
*CVSS v3.1

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

0
*Multiple Sources

Exploited in Wild

-
*KEV

Decision

-
*SSVC
Descriptions

Nextcloud Server is a Nextcloud package that handles data storage. A vulnerability in federated share exists in versions prior to 19.0.11, 20.0.10, and 21.0.2. An attacker can gain access to basic information about users of a server by accessing a public link that a legitimate server user added as a federated share. This happens because Nextcloud supports sharing registered users with other Nextcloud servers, which can be done automatically when selecting the "Add server automatically once a federated share was created successfully" setting. The vulnerability is patched in versions 19.0.11, 20.0.10, and 21.0.2 As a workaround, disable "Add server automatically once a federated share was created successfully" in the Nextcloud settings.

Nextcloud Server es un paquete de Nextcloud que se encarga del almacenamiento de datos. Se presenta una vulnerabilidad en el recurso compartido federado en las versiones anteriores a la 19.0.11, 20.0.10 y 21.0.2. Un atacante puede obtener acceso a información básica sobre los usuarios de un servidor al acceder a un enlace público que un usuario legítimo del servidor haya añadido como recurso compartido federado. Esto ocurre porque Nextcloud admite compartir usuarios registrados con otros servidores Nextcloud, lo que puede hacerse automáticamente al seleccionar el ajuste "Add server automatically once a federated share was created successfully". La vulnerabilidad está parcheada en versiones 19.0.11, 20.0.10 y 21.0.2 Como solución, deshabilitar la opción "Add server automatically once a federated share was created successfully" en la configuración de Nextcloud

*Credits: N/A
CVSS Scores
Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Changed
Confidentiality
High
Integrity
None
Availability
None
Attack Vector
Network
Attack Complexity
Low
Authentication
None
Confidentiality
Partial
Integrity
None
Availability
None
* Common Vulnerability Scoring System
SSVC
  • Decision:-
Exploitation
-
Automatable
-
Tech. Impact
-
* Organization's Worst-case Scenario
Timeline
  • 2021-05-12 CVE Reserved
  • 2021-06-01 CVE Published
  • 2024-02-15 EPSS Updated
  • 2024-08-03 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"
 < 19.0.11
Search vendor "Nextcloud" for product "Nextcloud Server" and version " < 19.0.11"
-
Affected
Nextcloud
Search vendor "Nextcloud"
 Nextcloud Server
Search vendor "Nextcloud" for product "Nextcloud Server"
 >= 20.0.0 < 20.0.10
Search vendor "Nextcloud" for product "Nextcloud Server" and version " >= 20.0.0 < 20.0.10"
-
Affected
Nextcloud
Search vendor "Nextcloud"
 Nextcloud Server
Search vendor "Nextcloud" for product "Nextcloud Server"
 >= 21.0.0 < 21.0.2
Search vendor "Nextcloud" for product "Nextcloud Server" and version " >= 21.0.0 < 21.0.2"
-
Affected