CVE-2021-32655 Files Drop public link can be added as federated share

Low 3.5 Published 1 Jun 2021 Updated 3 Aug 2024

Attackers can convert Files Drop links to federated shares, bypassing intended restrictions and granting unauthorized read access to shared data.

Exploited in the wild: Not known
Login needed: Any signed-in user
Attackable: Over the internet
Victim action needed: A user has to click or open something
Fix: None listed

What is CVE-2021-32655?

CVE-2021-32655 is a low-severity vulnerability in Nextcloud Nextcloud Server, published on 1 Jun 2021. Any signed-in user can exploit it over the network, and only if a user opens a file or follows a link.

Official description

Nextcloud Server is a Nextcloud package that handles data storage. In versions prior to 19.0.11, 20.0.10, and 21.0.2, an attacker is able to convert a Files Drop link to a federated share. This causes an issue on the UI side of the sharing user. When the sharing user opens the sharing panel and tries to remove the "Create" privileges of this unexpected share, Nextcloud server would silently grant the share read privileges. The vulnerability is patched in versions 19.0.11, 20.0.10 and 21.0.2. No workarounds are known to exist.

Weakness: CWE-241

Which versions are affected by CVE-2021-32655?

It affects 1 product.

Products include Nextcloud Nextcloud Server.

How do I fix CVE-2021-32655?

No fix has been published for CVE-2021-32655 yet. Limit exposure of the affected software until one is available.

Is CVE-2021-32655 being exploited?

There is no known exploitation of CVE-2021-32655 in the wild and no public exploit code.

All Nextcloud Nextcloud Server vulnerabilities

Sources

Also known as GHSA-grph-cm44-p3jv.