CVE-2021-25635 Content Manipulation with Certificate Validation Attack
Attackers can bypass certificate validation in LibreOffice to present modified ODF documents as validly signed by trusted parties.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Local or same network only
- Victim action needed
- A user has to click or open something
- Fix
- Available
What is CVE-2021-25635?
CVE-2021-25635 is a medium-severity vulnerability in Libreoffice Libreoffice, published on 21 Mar 2025. It can only be exploited from the same machine or local network, and only if a user opens a file or follows a link.
Official description
An Improper Certificate Validation vulnerability in LibreOffice allowed an attacker to self sign an ODF document, with a signature untrusted by the target, then modify it to change the signature algorithm to an invalid (or unknown to LibreOffice) algorithm and LibreOffice would incorrectly present such a signature with an unknown algorithm as a valid signature issued by a trusted person
This issue affects LibreOffice: from 7.0 before 7.0.5, from 7.1 before 7.1.1.
Weakness: CWE-295
Which versions are affected by CVE-2021-25635?
It affects 1 product.
Products include Libreoffice Libreoffice.
How do I fix CVE-2021-25635?
Upgrade to a fixed version.
Is CVE-2021-25635 being exploited?
There is no known exploitation of CVE-2021-25635 in the wild and no public exploit code.
Other vulnerabilities in Libreoffice Libreoffice
Sources
Also known as GHSA-r73f-2rxh-prfm.