Red Hat Security Advisory: libreoffice security update

Moderate

A vulnerability was found in LibreOffice that affects the Office URI Schemes. These schemes enable browser integration of LibreOffice with the MS SharePoint server. In LibreOffice, the links using the scheme 'vnd.libreoffice.command' could be constructed to call internal macros with arbitrary arguments, which, when clicked, or activated by document events, could result in arbitrary script execution without warning. The attacker must trick the targeted individual into opening a malicious file to trigger the exploit.

CWE-20 - Improper Input Validation

An Improper Certificate Validation vulnerability was found in LibreOffice, where determining if a trusted author signed a macro was done by only matching the serial number and issuer string of the used certificate with that of a trusted certificate. This is not sufficient to verify that the macro was actually signed with the certificate. This flaw allows an adversary to create an arbitrary certificate with a serial number and an issuer string identical to a trusted certificate which LibreOffice would present as belonging to the trusted author, potentially leading to the user executing arbitrary code contained in the improperly trusted macros.