Title: CVE-2019-9852 Insufficient URL encoding flaw in allowed script location check

Announced: August 15, 2019

Fixed in: 6.2.6/6.3.0


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-2018-16858, to avoid a directory traversal attack where scripts in arbitrary locations on the file system could be executed. However this new protection could be bypassed by a URL encoding attack.

In the fixed versions, the parsed url describing the script location is correctly encoded before further processing.


Thanks to Nils Emmerich of ERNW Research GmbH for discovering and reporting this issue