Three vulnerabilities have been disclosed in the LibreOffice and Apache OpenOffice office suites that allow attackers to prepare documents that look like they were signed by a trustworthy source, or change the date of an already signed document. The issues were fixed in Apache OpenOffice 4.1.11 and LibreOffice 7.0.6/7.1.2 releases under the guise of non-security bugs (LibreOffice 7.0.6 and 7.1.2 releases were published in early May, but the vulnerability has only now been disclosed).
- CVE-2021-41832, CVE-2021-25635 - Allows an attacker to sign an ODF document with an untrustworthy self-signed certificate, but by changing the digital signature algorithm to an incorrect or unsupported value, to display this document as trustworthy (a signature with an incorrect algorithm was processed as correct).
- CVE-2021-41830, CVE-2021-25633 - allows an attacker to create an ODF document or macro by combining data signed by different certificates in documentsignatures.xml and macrosignatures.xml files, which will be displayed in the interface as trustworthy, despite the presence additional content certified by another certificate.
- CVE-2021-41831, CVE-2021-25634 - allows you to make changes to an ODF document signed with a digital signature that distort the digital signature generation time shown to the user without violating the trust indication.
Source: opennet.ru