Vulnerability identifier: #VU7456

Vulnerability risk: Low

CVSSv3.1: 5.3 [CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N/E:U/RL:O/RC:C]

CVE-ID: CVE-2017-8559

CWE-ID: CWE-79

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Microsoft Exchange Server
Server applications / Mail servers

Vendor: Microsoft

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

The vulnerability is caused by incorrect filtration of input data by Microsoft Exchange Outlook Web Access (OWA). A remote attacker can trick the victim to follow a specially crafted link and execute arbitrary HTML and script code in victim’s browser in security 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.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Microsoft Exchange Server: 2013 Service Pack 1 15.00.0847.032 - 2013 Cumulative Update 16 15.00.1293.002, 2016 Cumulative Update 5 15.01.0845.034

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External links
http://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2017-8559

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Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability.