Cross-site scripting in Microsoft Exchange Server - #VU19077
Published: July 9, 2019
Vulnerability identifier: #VU19077
CSH Severity: Medium
CVSS v4.0: CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:N/SC:L/SI:L/SA:N/E:U/U:Green
CVE-ID: N/A
CWE-ID: CWE-79
Exploitation vector: Remote access
Exploit availability:
No public exploit available
Vendor: Microsoft
Affected software:
Microsoft Exchange Server
Microsoft Exchange Server
Detailed vulnerability description
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 SVG images. A remote attacker can send a specially crafted email message that contains a malicious SVG image and and execute arbitrary HTML and script code in user's browser in context of Outlook on the web (formerly known as Outlook Web App) 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
Vendor recommends to block SVG images via the Set-OwaMailboxPolicy command.