Zero-day vulnerability in Microsoft Office

Type confusion
CVE-2017-0262

The vulnerability was used by APT28 team along with another zero-day CVE-2017-0263.

Known malware:

GAMEFISH

Vulnerability details

Advisory: SB2017041210 - Two remote code execution vulnerabilities when processing EPS files in Microsoft Office

Vulnerable component: Microsoft Office

CVE-ID: CVE-2017-0262

CVSSv3 score: CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H/E:H/RL:O/RC:C

CWE-ID: CWE-843 - Type confusion

Description:

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

The vulnerability exists due to a type confusion error when processing EPS wiles within Microsoft Office documents. A remote unauthenticated attacker can create a specially crafted document, trick the victim into opening it and execute arbitrary code on the target system with privileges of the current victim.

Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.

Note: this vulnerability is being actively exploited in the wild.

External links:

https://www.fireeye.com/blog/threat-research/2017/05/eps-processing-zero-days.html
https://blogs.technet.microsoft.com/msrc/2017/05/09/coming-together-to-address-encapsulated-postscri...

About zero-day vulnerabilities

Zero-day vulnerability is an undisclosed vulnerability in software that hackers can exploit to compromise computer programs, gain unauthorized access to sensitive data, penetrate networks, etc. We consider vulnerability a zero-day when there is no solution provided from software vendor and the vulnerability is being actively exploited by malicious actors.

Zero-day candidate is a potential zero-day vulnerability in software which might have been used in targeted attacks, however there is no evidence to support this suggestion.