CVE-2021-32744: Collabora Online

High severity, CVSS 7.5. EPSS: 1.1% chance of exploitation in the next 30 days.

Collabora Online is a collaborative online office suite. In versions prior to 4.2.17-1 and version 6.4.9-5, unauthenticated attackers are able to gain access to files which are currently opened by other users in the Collabora Online editor. For successful exploitation the attacker is required to guess the file identifier - the predictability of this file identifier is dependent on external file-storage implementations (this is a potential "IDOR" - Insecure Direct Object Reference - vulnerability). Versions 4.2.17-1 and 6.4.9-5 contain patches for this issue. There is no known workaround except updating the Collabora Online application to one of the patched releases.

Affected products

• Collabora Online: before 4.2.17-1 (fixed in 4.2.17-1); from 6.4.0, before 6.4.9-5 (fixed in 6.4.9-5)

Published 2021-07-21. Last modified 2026-06-17.