SB2019071002 - Multiple vulnerabilities in Microsoft Exchange Server

Description

This security bulletin contains information about 2 secuirty vulnerabilities.

1) Cross-site scripting (CVE-ID: CVE-2019-1137)

The disclosed vulnerability allows a remote attacker to perform cross-site scripting (XSS) attacks.

The vulnerability exists due to insufficient sanitization of user-supplied data. A remote attacker can trick the victim to follow a specially crafted link and execute arbitrary HTML and script code in user's browser in context of vulnerable website.

Successful exploitation of this vulnerability may allow a remote attacker to steal potentially sensitive information, change appearance of the web page, perform phishing and drive-by-download attacks.

2) Improper Authentication (CVE-ID: CVE-2019-1136)

The vulnerability allows a remote attacker to escalate privileges within the Microsoft Exchange Server.

The vulnerability exists within the Exchange Web Services (EWS) feature when processing authentication tokens. A remote attacker with ability to perform man-in-the-middle (MitM) attack and forward the authentication request to Exchange server can impersonate victim and gain unauthorized access to the server. 

Remediation

Install update from vendor's website.

References

• https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2019-1137
• https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2019-1136