CVE-2022-26305: Execution of Untrusted Macros Due to Improper Certificate Validation

An Improper Certificate Validation vulnerability in LibreOffice existed where determining if a macro was signed by a trusted author 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. An adversary could therefore 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 to execute arbitrary code contained in macros improperly trusted. This issue affects: The Document Foundation LibreOffice 7.2 versions prior to 7.2.7; 7.3 versions prior to 7.3.1.