Vulnerability in Nextcloud
CVE-2021-32727
Nextcloud Android Client is the Android client for Nextcloud. Clients using the Nextcloud end-to-end encryption feature download the public and private key via an API endpoint. In versions prior to 3.16.1, the Nextcloud Android client skipped a step that involved the client checking if a private key belonged to a previously downloaded public certificate. If the Nextcloud instance served a malicious public key, the data would be encrypted for this key and thus could be accessible to a malicious actor. The vulnerability is patched in version 3.16.1. As a workaround, do not add additional end-to-end encrypted devices to a user account.
Vulnerability class: Improper Certificate Validation
EPSS: 0.007 (50.6th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 5.7 (Medium). Vector: CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:N/A:N.
Affected products
- Nextcloud
- Nextcloud Security-advisories — versions < 3.16.1
Weakness classification (CWE)
References
- security-advisories@github.com (x_refsource_CONFIRM, Third Party Advisory)
- security-advisories@github.com (Third Party Advisory, x_refsource_MISC)
- security-advisories@github.com (Permissions Required, x_refsource_MISC)
- security-advisories@github.com (Third Party Advisory, x_refsource_MISC)
Frequently asked questions
- What is CVE-2021-32727?
- CVE-2021-32727 is a medium-severity vulnerability in Nextcloud, classified under Improper Certificate Validation. CVSS score: 5.7/10. Published 2021-07-12.
- How severe is CVE-2021-32727?
- Medium severity. CVSS v3 base score is 5.7 out of 10.