CVE-2021-32656

Description

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.

CvssV3 impact

BaseSeverity

HIGH

ConfidentialityImpact

HIGH

AttackComplexity

LOW

Scope

CHANGED

AttackVector

NETWORK

AvailabilityImpact

NONE

IntegrityImpact

NONE

PrivilegesRequired

NONE

BaseScore

8.6

VectorString

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

Version

3.1

UserInteraction

NONE

CvssV2 impact

AccessComplexity

LOW

ConfidentialityImpact

PARTIAL

AvailabilityImpact

NONE

IntegrityImpact

NONE

BaseScore

5

VectorString

AV:N/AC:L/Au:N/C:P/I:N/A:N

Version

2.0

AccessVector

NETWORK

Authentication

NONE