CVE-2019-9854 - Improper Access Control

Severity

78%

Complexity

18%

Confidentiality

98%

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.

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.

CVSS 3.1 Base Score 7.8. CVSS Attack Vector: local. CVSS Attack Complexity: low. CVSS Vector: (CVSS:3.1/AV:L/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H).

CVSS 2.0 Base Score 6.8. CVSS Attack Vector: network. CVSS Attack Complexity: medium. CVSS Vector: (AV:N/AC:M/Au:N/C:P/I:P/A:P).

Overview

First reported 5 years ago

2019-09-06 19:15:00

Last updated 5 years ago

2019-12-20 14:19:00

Affected Software

LibreOffice LibreOffice

Canonical Ubuntu Linux 16.04 LTS (Long-Term Support)

16.04

Canonical Ubuntu Linux 18.04 LTS Edition

18.04

Canonical Ubuntu Linux 19.04

19.04

Debian Linux 8.0 (Jessie)

8.0

Debian Linux 9.0

9.0

Fedora 29

29

openSUSE Leap 15.0

15.0

OpenSUSE Leap 15.1

15.1

Red Hat Enterprise Linux (RHEL) 7.0 (7)

7.0

Red Hat Enterprise Linux 8.0

8.0

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