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. This issue affects: Document Foundation LibreOffice versions prior to 6.2.6.
The product prepares a structured message for communication with another component, but encoding or escaping of the data is either missing or done incorrectly. As a result, the intended structure of the message is not preserved.
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Ubuntu_linux | Canonical | 16.04 (including) | 16.04 (including) |
| Ubuntu_linux | Canonical | 18.04 (including) | 18.04 (including) |
| Ubuntu_linux | Canonical | 19.04 (including) | 19.04 (including) |
| Debian_linux | Debian | 8.0 (including) | 8.0 (including) |
| Debian_linux | Debian | 9.0 (including) | 9.0 (including) |
| Debian_linux | Debian | 10.0 (including) | 10.0 (including) |
| Fedora | Fedoraproject | 29 (including) | 29 (including) |
| Leap | Opensuse | 15.0 (including) | 15.0 (including) |
| Leap | Opensuse | 15.1 (including) | 15.1 (including) |
| Red Hat Enterprise Linux 7 | RedHat | libreoffice-1:5.3.6.1-24.el7 | * |
| Red Hat Enterprise Linux 8 | RedHat | libreoffice-1:6.0.6.1-20.el8 | * |
| Libreoffice | Ubuntu | bionic | * |
| Libreoffice | Ubuntu | devel | * |
| Libreoffice | Ubuntu | disco | * |
| Libreoffice | Ubuntu | trusty | * |
| Libreoffice | Ubuntu | upstream | * |
| Libreoffice | Ubuntu | xenial | * |
Improper encoding or escaping can allow attackers to change the commands that are sent to another component, inserting malicious commands instead. Most products follow a certain protocol that uses structured messages for communication between components, such as queries or commands. These structured messages can contain raw data interspersed with metadata or control information. For example, “GET /index.html HTTP/1.1” is a structured message containing a command (“GET”) with a single argument ("/index.html") and metadata about which protocol version is being used (“HTTP/1.1”). If an application uses attacker-supplied inputs to construct a structured message without properly encoding or escaping, then the attacker could insert special characters that will cause the data to be interpreted as control information or metadata. Consequently, the component that receives the output will perform the wrong operations, or otherwise interpret the data incorrectly.