title: Secret Circle can be joined without approval in Nextcloud Circles
description: Nextcloud Circles is an open source social network built for the nextcloud ecosystem. In affected versions the Nextcloud Circles application allowed any user to join any "Secret Circle" without approval by the Circle owner leaking private information. It is recommended that Nextcloud Circles is upgraded to 0.19.15, 0.20.11 or 0.21.4. There are no workarounds for this issue.
problem types: CWE-639: Authorization Bypass Through User-Controlled Key
affected:
{
product: security-advisories
vendor: nextcloud
versions:
status: affected, version: < 0.19.15
status: affected, version: >= 0.20.0, < 0.20.11
status: affected, version: >= 0.21.0, < 0.21.4
}
metrics:
cvssV3_1: [
attackComplexity: LOW
attackVector: NETWORK
availabilityImpact: NONE
baseScore: 6.5
baseSeverity: MEDIUM
confidentialityImpact: HIGH
integrityImpact: NONE
privilegesRequired: LOW
scope: UNCHANGED
userInteraction: NONE
vectorString: CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
version: 3.1
]