KLA11102
Multiple vulnerabilities in Microsoft Exchange Server

Multiple serious vulnerabilities have been found in Microsoft Exchange Server. Malicious users can exploit these vulnerabilities to obtain sensitive information and gain privileges.

Below is a complete list of vulnerabilities:

1. An incorrect parsing of Calendar-related messages can be exploited by sending Calendar-related messages with specially designed tags to server to obtain sensitive information.
2. An improper validation of webrequests in Microsoft Exchange (OWA) Outlook Web Access can be exploited remotely by convincing a user to click a specially designed link to gain privileges.

NB: Not every vulnerability already has CVSS rating, so cumulative CVSS rating can be not representative.

NB: These vulnerabilities do not have any public CVSS rating, so rating can be changed by the time.

Microsoft Exchange Server 2013 Cumulative Update 16
Microsoft Exchange Server 2013 Cumulative Update 17
Microsoft Exchange Server 2013 Service Pack 1
Microsoft Exchange Server 2016 Cumulative Update 5
Microsoft Exchange Server 2016 Cumulative Update 6

Install necessary updates from the KB section, that are listed in your Windows Update (Windows Update usually can be accessed from the Control Panel)