tl:dr upgrade to LibreOffice 7-2 to 7.2.5 (or libreoffice 7.3.0) LibreOffice supports digital signatures of ODF documents and macros within documents, presenting visual aids that no alteration of the document occurred since the last signing and that the signature is valid.
The Network and Data Security group at Ruhr University Bochum reported a flaw with the implementation of this. CVE-2021-25636 Incorrect trust validation of signature with ambiguous KeyInfo children 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 contain both "X509Data" and "KeyValue" children of the "KeyInfo" tag[1], which when opened caused LibreOffice to verify using the "KeyValue" but to report verification with the unrelated "X509Data" value. In versions >= 7.2.5 (and >= 7.3.0) certificate validation is now configured to only consider X509Data children to limit validation to X509 certificates only. [1] https://www.w3.org/TR/xmldsig-core1/#sec-KeyInfo -- To unsubscribe e-mail to: discuss+unsubscr...@documentfoundation.org Problems? https://www.libreoffice.org/get-help/mailing-lists/how-to-unsubscribe/ Posting guidelines + more: https://wiki.documentfoundation.org/Netiquette List archive: https://listarchives.documentfoundation.org/www/discuss/ Privacy Policy: https://www.documentfoundation.org/privacy
