Remote code execution in Microsoft VBScript engine

Published: 2018-04-21 | Updated: 2018-05-08
Severity Critical
Patch available YES
Number of vulnerabilities 1
CVE ID CVE-2018-8174
Exploitation vector Network
Public exploit This vulnerability is being exploited in the wild.
Vulnerable software Windows Subscribe
Windows Live Messenger
Windows Server
Vendor Microsoft

Security Advisory

This security advisory describes one critical risk vulnerability.

The vulnerability description was updated on May 8, 2018 according to Microsoft advisory.

1) Memory corruption

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-2018-8174

CWE-ID: CWE-119 - Improper Restriction of Operations within the Bounds of a Memory Buffer


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

The vulnerability exists due to a boundary error within the VBScript engine. A remote attacker can trick the victim into visiting a specially crafted website or open a malicious Office file and execute arbitrary code on the target system.

Note: the vulnerability is being actively exploited in the wild against victims in Asia region. The vulnerability is dubbed "double play".


Install updates from vendor's website.

Vulnerable software versions

Windows: 7, 10, RT 8.1

Windows Live Messenger: 8.1

Windows Server: 2008, 2008 R2, 2012, 2012 R2, 2016

CPE External links

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

Yes. This vulnerability is being exploited in the wild.