Title: CVE-2024-5261: TLS certificate are not properly verified when utilizing LibreOfficeKit

Announced: Jun 25, 2024

Fixed in: LibreOffice 24.2.4


LibreOfficeKit can be used for accessing LibreOffice functionality through C/C++. Typically this is used by third party components to reuse LibreOffice as a library to convert, view or otherwise interact with documents.

LibreOffice internally makes use of "curl" to fetch remote resources such as images hosted on webservers.

In affected versions of LibreOffice, when used in LibreOfficeKit mode only, then curl's TLS certification verification was disabled (CURLOPT_SSL_VERIFYPEER of false)

In the fixed versions curl operates in LibreOfficeKit mode the same as in standard mode with CURLOPT_SSL_VERIFYPEER of true.

Users are recommended to upgrade to 24.2.4 to avoid this flaw.


Thanks to OpenSource Security GmbH on behalf of the German Federal Office for Information Security for finding and reporting this issue.
Thanks to Thorsten Behrens of allotropia for providing a fix.