Alert - Google Chrome Zero-day Vulnerability

Number: AL19-019
Date: 4 November 2019

AUDIENCE
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This Alert is intended for IT professionals and managers of notified organizations.

PURPOSE
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An Alert is used to raise awareness of a recently identified cyber threat Cyber threatA threat actor, using the internet, who takes advantage of a known vulnerability in a product for the purposes of exploiting a network and the information the network carries. that may impact cyber information assets, and to provide additional detection DetectionThe monitoring and analyzing of system events in order to identify unauthorized attempts to access system resources. and mitigation advice to recipients.  The Canadian Centre for Cyber Security Cyber securityThe protection of digital information, as well as the integrity of the infrastructure housing and transmitting digital information. More specifically, cyber security includes the body of technologies, processes, practices and response and mitigation measures designed to protect networks, computers, programs and data from attack, damage or unauthorized access so as to ensure confidentiality, integrity and availability. ("Cyber Centre") is also available to provide additional assistance regarding the content of this Alert to recipients as requested.

DETAILS
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The Cyber Centre has become aware that exploits for CVE-2019-13720 have been observed. On 31 October 2019, Google released a patch for Google Chrome to address this high severity zero-day, which is tied to the audio component of Google Chrome. This ‘use-after-free’ vulnerability VulnerabilityA flaw or weakness in the design or implementation of an information system or its environment that could be exploited to adversely affect an organization's assets or operations. , which is when an application tries to reference memory that has since been freed or deleted, can lead to arbitrary code execution. An actor could exploit the vulnerability by crafting a malicious webpage that takes advantage of the vulnerable Chrome component and then lure users into visiting the webpage.

A second high severity use-after-free vulnerability, CVE-2019-13721, has also been patched in the latest update. CVE-2019-13721 has not been observed as being actively exploited.

SUGGESTED ACTIONS
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- Update Google Chrome to the latest version, namely, 78.0.3904.87 at the time of publishing.
- Always exercise caution when receiving an unexpected email or email reply containing an attachment or URL, even when from a trusted source. If the email seems unusual, contact the sender to confirm the authenticity of the attachment.
- Follow the Cyber Centre’s guidance to stay CyberSafe.

REFERENCES
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Google Chrome Blog:
https://chromereleases.googleblog.com/2019/10/stable-channel-update-for-desktop_31.html

ZDNet Article:
https://www.zdnet.com/article/halloween-scare-google-discloses-chrome-zero-day-exploited-in-the-wild/

Five Practical Ways to Make Yourself CyberSafe:
https://cyber.gc.ca/en/guidance/five-practical-ways-make-yourself-cybersafe

NOTE TO READERS
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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 Critical infrastructureProcesses, systems, facilities, technologies, networks, assets, and services essential to the health, safety, security, or economic well-being of Canadians and the effective functioning of government. Critical infrastructure can be stand-alone or interconnected and interdependent within and across provinces, territories, and national borders. Disruptions of critical infrastructure could result in catastrophic loss of life, adverse economic effects, and significant harm to public confidence. , 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.