CVE-2021-32726 Webauthn tokens not removed after user has been deleted
Attackers can hijack accounts by reusing deleted usernames because WebAuthn tokens were not removed, allowing unauthorized access to Nextcloud servers.
- 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
- Available
What is CVE-2021-32726?
CVE-2021-32726 is a high-severity authentication bypass vulnerability in Nextcloud Nextcloud Server, published on 12 Jul 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 19.0.13, 20.011, and 21.0.3, webauthn tokens were not deleted after a user has been deleted. If a victim reused an earlier used username, the previous user could gain access to their account. The issue was fixed in versions 19.0.13, 20.0.11, and 21.0.3. There are no known workarounds.
Which versions are affected by CVE-2021-32726?
It affects 1 product.
Products include Nextcloud Nextcloud Server.
How do I fix CVE-2021-32726?
Upgrade to a fixed version.
Upgrade, and rotate credentials and sessions that may have been exposed. More about Authentication bypass.
Is CVE-2021-32726 being exploited?
There is no known exploitation of CVE-2021-32726 in the wild and no public exploit code.
Other vulnerabilities in Nextcloud Nextcloud Server
- CVE-2021-32802 Preview generation used third-party library not suited for user-generated content in Nextcloud server
- CVE-2023-26482 Scope of workflow operations is not validated in nextcloud server
- CVE-2018-3775 Auth bypass in Nextcloud Server
- CVE-2023-35172 Nextcloud Server password reset endpoint is not brute force protected
- CVE-2023-32320 Nextcloud Server's brute force protection allows someone to send more requests than intended
Sources
Also known as GHSA-6qr9-c846-j8mg.