CVE-2021-32728
What it is
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.
At a glance
- Exploitability
- Can be exploited over the network with a low-privilege account. High risk of data exposure.
- Exploit odds
- 0.9% chance of exploitation in the next 30 days (EPSS).
- Fix
- A patch, advisory or fixed version is referenced. Upgrade or apply it.
Timeline
- PublishedDisclosed publicly on CVE.org and NVD
- Last updatedMost recent change to the record
Why it ranks here
- Exploited in the wild: no, CISA does not list it.
- Exploit odds: 0.9% in the next 30 days (EPSS).
- Severity: 6.5 MEDIUM (CVSS).
- Fix: a patch or advisory is linked.
Details
- Published
- Last modified
- Exploit probability
- 0.9% · EPSS, next 30 days
- Weakness
- CWE-295 · Improper certificate validation
- Record status
- Modified
Affected
- Nextcloud Desktop < 3.3.0
- Debian Linux 10.0
- Debian Linux 11.0
Attack profile CVSS 3.1 · 6.5
- Attack vector
- Network
- Complexity
- Low
- Privileges needed
- Low
- User interaction
- None
- Scope
- Unchanged
- Confidentiality
- High
- Integrity
- None
- Availability
- None
Raw vector
CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:N/A:N
Is it in your code?
Hand this to your coding agent. It searches your project for the affected products and checks versions. Nothing leaves your machine.
Read https://cve-list.com/agent/cve/CVE-2021-32728.md and follow it. Check whether this project is affected by CVE-2021-32728. Read only. Don't change anything and don't upload my code. Tell me yes, no or not sure, with the file as proof.
Fix and advisories
- https://github.com/nextcloud/desktop/pull/3338
- https://github.com/nextcloud/security-advisories/security/advisories/GHSA-f5fr-5gcv-6cc5
- https://github.com/nextcloud/desktop/pull/3338
- https://github.com/nextcloud/security-advisories/security/advisories/GHSA-f5fr-5gcv-6cc5
References
- https://github.com/nextcloud/desktop/pull/3338
- https://github.com/nextcloud/security-advisories/security/advisories/GHSA-f5fr-5gcv-6cc5
- https://hackerone.com/reports/1189162
- https://www.debian.org/security/2021/dsa-4974
- https://github.com/nextcloud/desktop/pull/3338
- https://github.com/nextcloud/security-advisories/security/advisories/GHSA-f5fr-5gcv-6cc5
- https://hackerone.com/reports/1189162
- https://www.debian.org/security/2021/dsa-4974