An Improper Certificate Validation vulnerability in LibreOffice allowed an attacker to create a digitally signed ODF document, by manipulating the documentsignatures.xml or macrosignatures.xml stream within the document to combine multiple certificate data, which when opened caused LibreOffice to display a validly signed indicator but whose content was unrelated to the signature shown. External Reference: https://www.libreoffice.org/about-us/security/advisories/CVE-2021-25633
RHEL 8.6.0 and below are all affected by this flaw. RHEL 9 uses an updated version which is not exposed to the flaw. LibreOffice improperly validated signatures which by manipulation of signatures xml files allowed for multiple certificate data to be combined which led to LibreOffice believing that the signature was valid, when the content was not at all valid for the signature.
This issue has been addressed in the following products: Red Hat Enterprise Linux 8 Via RHSA-2022:1766 https://access.redhat.com/errata/RHSA-2022:1766
This bug is now closed. Further updates for individual products will be reflected on the CVE page(s): https://access.redhat.com/security/cve/cve-2021-25633