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OpenAdvisories
Medium · 6.5 CVE-2021-32728 EUVD-2021-19510

End-to-end encryption device setup did not verify public key

Published Aug 18, 2021 · Updated Aug 3, 2024 · Assigned by GitHub_M

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.

Affected products

VendorProductAffectedFixed
nextcloud security-advisories < 3.3.0 —

Fixed in Linux distributions

Distributions backport fixes, so the version that fixes this vulnerability differs per release — upgrade to at least the version shown. From the distributions' security trackers and advisories.

ReleasePackageFixed inAdvisory
Debian 14 nextcloud-desktop 3.3.1-1 —
Debian 13 nextcloud-desktop 3.3.1-1 —
Debian 12 nextcloud-desktop 3.3.1-1 —
Debian 11 nextcloud-desktop 3.1.1-2+deb11u1 DSA-4974-1
Debian 10 nextcloud-desktop 2.5.1-3+deb10u2 DSA-4974-1
ReleasePackageFixed inAdvisory
Ubuntu 22.04 LTS nextcloud-desktop No fix yet —
Ubuntu 20.04 LTS nextcloud-desktop No fix yet —

Advisories 1

References