LibreOffice has a feature where documents can specify that pre-installed macros can be executed on various script events such as mouse-over, document-open etc. Access is intended to be restricted to scripts under the share/Scripts/python, user/Scripts/python sub-directories of the LibreOffice install. Protection was added, to address CVE-2019-9852, to avoid a directory traversal attack where scripts in arbitrary locations on the file system could be executed by employing a URL encoding attack to defeat the path verification step. However this protection could be bypassed by taking advantage of a flaw in how LibreOffice assembled the final script URL location directly from components of the passed in path as opposed to solely from the sanitized output of the path verification step. This issue affects: Document Foundation LibreOffice 6.2 versions prior to 6.2.7; 6.3 versions prior to 6.3.1. References: https://www.libreoffice.org/about-us/security/advisories/CVE-2019-9854/ https://seclists.org/bugtraq/2019/Sep/17
Created libreoffice tracking bugs for this issue: Affects: fedora-all [bug 1769909]
External References: https://www.libreoffice.org/about-us/security/advisories/CVE-2019-9854/
An attacker is able to trigger execution of arbitrary python scripts, previously placed at certain locations in the file system, when libreoffice documents are opened and certain actions are performed. However there are several conditions to successful exploitation: 1. The document needs to have macros associated with certain actions like opening the document, mouse over etc. This can be achieved by sending malicious files to users via email etc and social engineering them to open the document. 2. The malicious script needs to exists on the file system to be executed.
This issue has been addressed in the following products: Red Hat Enterprise Linux 7 Via RHSA-2020:1151 https://access.redhat.com/errata/RHSA-2020:1151
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-2019-9854
This issue has been addressed in the following products: Red Hat Enterprise Linux 8 Via RHSA-2020:1598 https://access.redhat.com/errata/RHSA-2020:1598