CVE-2019-9852

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

Description:

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.

Credits:

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

References:

    CVE-2019-9852