SB2018031309 - Multiple vulnerabilities in Microsoft Exchange OWA

Description

This security bulletin contains information about 3 secuirty vulnerabilities.

1) Open redirect (CVE-ID: CVE-2018-0924)

The vulnerability allows a remote attacker to redirect users to malicious websites.

The vulnerability exists due to insufficient validation of the redirected URL in Outlook Web Access (OWA) Light. A remote attacker can create a specially crafted link and perform phishing attacks against OWA users.

2) Information disclosure (CVE-ID: CVE-2018-0941)

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

The vulnerability exists due to the way that Microsoft Exchange Server handles importing data. A remote attacker with ability to upload a specially crafted file to Microsoft Exchange Outlook Web Access (OWA), can get access to potentially sensitive information.

3) Cross-site scripting (CVE-ID: CVE-2018-0940)

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 passed via hyperlinks in the email body. A remote attacker can create a specially crafted email message and execute arbitrary HTML and script code in user's browser in context of Outlook Web Access (OWA) 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.

Remediation

Install update from vendor's website.

References

• https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2018-0924
• https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2018-0941
• https://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2018-0940