Path Traversal in Document Foundation Libreoffice

CVE-2019-9854

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.

Vulnerability class: Path Traversal (Directory Traversal)

EPSS: 0.019 (77.9th percentile) — read the EPSS interpretation.

CVSS v3 metric

CVSS v3 base score 7.8 (High). Vector: CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H.

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2019-9854?
CVE-2019-9854 is a high-severity vulnerability in Document Foundation Libreoffice, classified under Path Traversal. CVSS score: 7.8/10. Published 2019-09-06.
How severe is CVE-2019-9854?
High severity. CVSS v3 base score is 7.8 out of 10.