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

Published: 2017-04-12 | Updated: 2017-05-10
Severity 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 Subscribe
Vendor Microsoft

Security Advisory

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

Severity: Critical

CVSSv3: 9.2 [CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H/E:H/RL:O/RC:C] [PCI]

CVE-ID: CVE-2017-0261

CWE-ID: CWE-416 - Use After Free

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, 2013, 2013 RT, 2016

CPE External links

https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/2017-2605
https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2017-0261
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...

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 an attachment in an e-mail message.

Is there known malware, which exploits this vulnerability?

Yes. This vulnerability is being exploited in the wild.

2) Type confusion

Severity: Critical

CVSSv3: 9.2 [CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:C/C:H/I:H/A:H/E:H/RL:O/RC:C] [PCI]

CVE-ID: CVE-2017-0262

CWE-ID: CWE-843 - Access of Resource Using Incompatible Type ('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.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Microsoft Office: 2010, 2013, 2013 RT, 2016

CPE External links

https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2017-0262
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...

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 an attachment in an e-mail message.

Is there known malware, which exploits this vulnerability?

Yes. This vulnerability is being exploited in the wild.