CVE-2021-32728
If the Nextcloud instance serves a malicious public key, the data would be encrypted for this key and thus could be accessible to a malicious actor.
Does this matter?
Lower severity and a low EPSS score (0.85%). Track it; it rarely justifies an emergency change on its own.
Description
The Nextcloud Desktop Client is a tool to synchronize files from Nextcloud Server with a computer. Clients using the Nextcloud end-to-end encryption feature download the public and private key via an API endpoint. In versions prior to 3.3.0, the Nextcloud Desktop client fails to check if a private key belongs to previously downloaded public certificate. If the Nextcloud instance serves a malicious public key, the data would be encrypted for this key and thus could be accessible to a malicious actor. This issue is fixed in Nextcloud Desktop Client version 3.3.0. There are no known workarounds aside from upgrading.
- CVSS 3.1
- 6.5 MEDIUMCVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
- EPSS
- 0.85% probability · 58th percentile
- Public exploits
- None in Exploit-DB
- CISA KEV
- Not listed
- Weakness
- CWE-295
- Affected
- nextcloud/desktop · debian/debian linux
- Source
- security-advisories@github.com
EPSS 0.9% since 26 October 2026; no change recorded yet. Points are recorded when the score first appears and whenever it moves by a percentage point or more.
References
- https://github.com/nextcloud/desktop/pull/3338Patch, Third Party Advisory
- https://github.com/nextcloud/security-advisories/security/advisories/GHSA-f5fr-5gcv-6cc5Exploit, Third Party Advisory
- https://hackerone.com/reports/1189162Exploit, Third Party Advisory
- https://www.debian.org/security/2021/dsa-4974Third Party Advisory
- https://github.com/nextcloud/desktop/pull/3338Patch, Third Party Advisory
- https://github.com/nextcloud/security-advisories/security/advisories/GHSA-f5fr-5gcv-6cc5Exploit, Third Party Advisory
- https://hackerone.com/reports/1189162Exploit, Third Party Advisory
- https://www.debian.org/security/2021/dsa-4974Third Party Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA, exploits from Exploit-DB. Refreshed daily. Download this record as JSON.