CVE-2021-25633 : Security Advisory and Response

A vulnerability labeled CVE-2021-25633 has been identified in LibreOffice, a popular open-source office suite developed by The Document Foundation. The vulnerability is related to improper certificate validation, allowing attackers to manipulate digitally signed ODF documents. Here's what you need to know about CVE-2021-25633.

Understanding CVE-2021-25633

This section will provide a detailed overview of the CVE-2021-25633 vulnerability in LibreOffice.

What is CVE-2021-25633?

CVE-2021-25633 is a vulnerability in LibreOffice that enables attackers to create digitally signed ODF documents by exploiting improper certificate validation mechanisms. This manipulation could result in misleading visual aids indicating document integrity when, in fact, the content has been tampered with.

The Impact of CVE-2021-25633

The vulnerability affects LibreOffice versions 7.0 prior to 7.0.6 and versions 7.1 prior to 7.1.2. If exploited, it could lead to the display of false validly signed indicators, misguiding users about the document's authenticity.

Technical Details of CVE-2021-25633

In this section, we will dive into the technical specifics of the CVE-2021-25633 vulnerability.

Vulnerability Description

LibreOffice's support for digital signatures of ODF documents and macros allows attackers to merge multiple certificate data within a document. This can deceive users into believing that a document is validly signed when its content doesn't match the displayed signature.

Affected Systems and Versions

The Document Foundation LibreOffice versions 7-0 (prior to 7.0.6) and 7-1 (prior to 7.1.2) are susceptible to this vulnerability.

Exploitation Mechanism

Attackers can exploit the vulnerability by manipulating the documentsignatures.xml or macrosignatures.xml stream within a document, creating misleading digital signatures.

Mitigation and Prevention

Learn how to address and prevent the CVE-2021-25633 vulnerability in LibreOffice.

Immediate Steps to Take

For immediate protection, users are advised to update their LibreOffice installations to versions 7.0.6, 7.1.2, or 7.2.0, which contain fixes for this vulnerability.

Long-Term Security Practices

Incorporating secure document handling protocols and conducting regular security audits can enhance the resilience of systems against similar vulnerabilities.

Patching and Updates

Stay informed about the latest security patches and updates released by The Document Foundation to safeguard your systems against known vulnerabilities.