Vulnerability identifier: #VU21035

Vulnerability risk: Medium

CVSSv3.1: 4.1 [CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:L/I:L/A:N/E:U/RL:O/RC:C]

CVE-ID: CVE-2019-1266

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 exists due to insufficient sanitization of user-supplied data in Outlook Web App (OWA). A remote attacker can trick the victim to click on 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.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Microsoft Exchange Server: 2016 Cumulative Update 12 15.01.1713.005 - 2016 Cumulative Update 13 15.01.1779.002, 2019 Cumulative Update 1 15.02.0330.005 - 2019 Cumulative Update 2 15.02.0397.003

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External links
http://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2019-1266

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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.