Two remote code execution vulnerabilities when processing EPS files in Microsoft Office

Published: 2017-04-12 | Updated: 2017-05-10

Risk	Critical
Patch available	YES
Number of vulnerabilities	2
CVE-ID	CVE-2017-0261 CVE-2017-0262
CWE-ID	CWE-416 CWE-843
Exploitation vector	Network
Public exploit	Vulnerability #1 is being exploited in the wild. Vulnerability #2 is being exploited in the wild.
Vulnerable software	Microsoft Office Client/Desktop applications / Office applications
Vendor	Microsoft

Security Bulletin

This security bulletin contains information about 2 vulnerabilities.

Changelog
--2017-05-09--
1) Patch was released for zero-day vulnerability CVE-2017-0261.
2) Second zero-day vulnerability in EPS handling was added.
3) Links were added to FireEye and Microsoft.

1) Use-after-free

EUVDB-ID: #VU6296

Risk: Critical

CVSSv3.1: 9.2 [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]

CVE-ID: CVE-2017-0261

CWE-ID: CWE-416 - Use After Free

Exploit availability: No

Description

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

The vulnerability exists due to a use-after-free error when processing EPS images within Microsoft Office files. A remote attacker can create a specially crafted Office file with malicious EPS image, trick the victim into opening it and execute arbitrary code on the target system with privileges of the current user.

Successful exploitation of this vulnerability may allow an attacker to compromise vulnerable system.

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

Mitigation

Install update from vendor's website.

Vulnerable software versions

Microsoft Office: 2010 - 2016

CPE2.3

External links

http://portal.msrc.microsoft.com/en-US/security-guidance/advisory/2017-2605
http://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2017-0261
http://www.fireeye.com/blog/threat-research/2017/05/eps-processing-zero-days.html
http://blogs.technet.microsoft.com/msrc/2017/05/09/coming-together-to-address-encapsulated-postscri...

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?

Yes. This vulnerability is being exploited in the wild.

2) Type confusion

EUVDB-ID: #VU6459