Remote code execution in LibreOffice

1) Input validation error

EUVDB-ID: #VU21398

Risk: High

CVSSv3.1: 7 [CVSS:3.1/AV:N/AC:L/PR:L/UI:R/S:U/C:H/I:H/A:H/E:U/RL:O/RC:C]

CVE-ID: CVE-2019-9853

CWE-ID: CWE-20 - Improper input validation

Exploit availability: No

Description

The vulnerability allows a remote attacker to execute arbitrary code on the target system.

The vulnerability exists due to insufficient validation of user-supplied input when decoding URL in macro location. While documents were correctly detected as containing macros, and prompted the user to their existence within the documents, but macros within the document were subsequently not controlled by the security settings. A remote attacker can create a specially crafted document that once opened will execute arbitrary macro on the system with privileges of the current user.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

LibreOffice: 6.1.6.3 - 6.3.0.2

External links

http://www.libreoffice.org/about-us/security/advisories/cve-2019-9853/

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote authenticated user via the Internet.

How the attacker can exploit this vulnerability?

The attacker would have to trick the victim to visit a specially crafted website or open a file.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.