Arbitrary file disclosure in LibreOffice

1) Information disclosure

EUVDB-ID: #VU10444

Risk: Low

CVSSv3.1: 4.2 [CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:N/A:N/E:P/RL:O/RC:C]

CVE-ID: CVE-2018-6871,CVE-2018-1055

CWE-ID: CWE-200 - Information exposure

Exploit availability: Yes

Description

The vulnerability allows a remote attacker to gain access to potentially sensitive information.

The vulnerability exists in LibreOffice Calc, which supports COM.MICROSOFT.WEBSERVICE function to obtain data by URL. The application allows WEBSERVICE to take a local file URL (e.g file://) which can be used to inject local files into the spreadsheet without warning the user. Subsequent formulas can operate on that inserted data and construct a remote URL. A remote attacker can create a specially crafted document, trick the victim into opening it and use  WEBSERVICE functionality to send arbitrary local files to the attacker's controlled server.

Mitigation

Update to version 5.4.5.1 or 6.0.1.1.

Vulnerable software versions

LibreOffice: 5.4.0.1 - 6.0.0.3

External links

http://www.libreoffice.org/about-us/security/advisories/cve-2018-1055/

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker 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. However, proof of concept for this vulnerability is available.