Number: AL18-17
Date: 19 December 2018
Purpose
An ALERT is used to raise awareness of a recently identified cyber threat that may impact cyber information assets, and to provide additional detection and mitigation advice to recipients. (The Canadian Centre for Cyber Security ("Cyber Centre") is also available to provide additional assistance regarding the content of this ALERT to recipients as requested.)
Assessment
The goal of this Alert is to bring heightened attention to a vulnerability in Internet Explorer for which there is currently a patch available. The vulnerability can be exploited by deceiving an end user into opening a maliciously-crafted website. Exploitation can lead to remote code execution on the affected computer. There are reports of this exploit currently being used in the wild.
Internet Explorer 9 to 11 on Windows 7 to 10, Server 2008 to 2019, and RT 8.1 are affected. Server editions which run IE in restricted (Enhanced Security Configuration) mode will not allow this vulnerability to be exploited unless the server website is added to the Internet Explorer Trusted sites zone.
CVE reference: CVE-2018-8653
Suggested action
- The Cyber Centre recommends that organizations update Internet Explorer as soon as possible.
- Do not open links to unknown websites.
- Do not browse the internet while logged in with a high privilege account such as Administrator.
- Do not disable Enhanced Security Configuration mode in Internet Explorer on Windows Servers.
- Ensure only validated, necessary sites are added to the Internet Explorer Trusted sites zone.
References
Microsoft Security Bulletin: https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2018-8653
Note to readers
The Canadian Centre for Cyber Security (Cyber Centre) operates as part of the Communications Security Establishment. We are Canada's national authority on cyber security and we lead the government's response to cyber security events. As Canada's national computer security incident response team, the Cyber Centre works in close collaboration with government departments, critical infrastructure, Canadian businesses and international partners to prepare for, respond to, mitigate, and recover from cyber events. We do this by providing authoritative advice and support, and coordinating information sharing and incident response. The Cyber Centre is outward-facing, welcoming partnerships that help build a stronger, more resilient cyber space in Canada.