SB2017091214 - Two vulnerabilities in Microsoft Exchange Server

Description

This security bulletin contains information about 2 secuirty vulnerabilities.

1) Cross-site scripting (CVE-ID: CVE-2017-8758)

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) Information disclosure (CVE-ID: CVE-2017-11761)

The vulnerability allows a remote attacker to obtain potentially sensitive information.

The vulnerability exists due to improper input sanitization issue in Microsoft Exchange. A remote attacker can send Calendar-related messages containing specially crafted tags to an Exchange server, trick the victim into observing telemetry from these requests and discerning properties of internal hosts intended to be hidden from the Internet, and identify the existence of RFC1918 addresses on the local network from a client on the Internet.

Remediation

Install update from vendor's website.

References

• https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2017-8758
• https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2017-11761