September 10, 2019
Microsoft Exchange Server is prone to a security vulnerability that may allow attackers to conduct spoofing attacks. An attacker can exploit this issue to conduct spoofing attacks and perform unauthorized actions; other attacks are also possible.
- Microsoft Exchange Server 2016 Cumulative Update 12
- Microsoft Exchange Server 2016 Cumulative Update 13
- Microsoft Exchange Server 2019 Cumulative Update 1
- Microsoft Exchange Server 2019 Cumulative Update 2
Run all software as a nonprivileged user with minimal access rights.
To reduce the impact of latent vulnerabilities, always run nonadministrative software as an unprivileged user with minimal access rights.
Deploy network intrusion detection systems to monitor network traffic for malicious activity.
Deploy NIDS to monitor network traffic for signs of anomalous or suspicious activity. This includes but is not limited to unexplained incoming and outgoing traffic. This may indicate exploit attempts or activity that results from successful exploits.
Do not follow links provided by unknown or untrusted sources.
Never follow links provided by unknown or untrusted sources.
Set web browser security to disable the execution of script code or active content.
Since a successful exploit of this issue allows malicious code to execute in web clients, consider disabling support for script code and active content within the client browser. Note that this mitigation tactic might adversely affect legitimate websites that rely on the execution of browser-based script code.
Updates are available. Please see the references or vendor advisory for more information.
© 1995- Symantec Corporation
Permission to redistribute this alert electronically is granted as long as it is not edited in any way unless authorized by Symantec Security Response. Reprinting the whole or part of this alert in any medium other than electronically requires permission from firstname.lastname@example.org.
The information in the advisory is believed to be accurate at the time of publishing based on currently available information. Use of the information constitutes acceptance for use in an AS IS condition. There are no warranties with regard to this information. Neither the author nor the publisher accepts any liability for any direct, indirect, or consequential loss or damage arising from use of, or reliance on, this information.
Symantec, Symantec products, Symantec Security Response, and email@example.com are registered trademarks of Symantec Corp. and/or affiliated companies in the United States and other countries. All other registered and unregistered trademarks represented in this document are the sole property of their respective companies/owners.