#VU21398 Input validation error in LibreOffice - CVE-2019-9853

Vulnerability identifier: #VU21398

Vulnerability risk: High

CVSSv4.0: 4 [CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:U/U:Amber]

CVE-ID: CVE-2019-9853

CWE-ID: CWE-20

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
LibreOffice
Client/Desktop applications / Office applications

Vendor: LibreOffice

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, 6.2.0.0 - 6.2.0.3, 6.2.1.1 - 6.2.1.2, 6.2.2.1 - 6.2.2.2, 6.2.3.1 - 6.2.3.2, 6.2.4.1 - 6.2.4.2, 6.2.5.1 - 6.2.5.2, 6.2.6.1, 6.3.0.0 - 6.3.0.2

---

External links
https://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.

Is there known malware, which exploits this vulnerability?

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