#VU15547 Logic error in Microsoft Office and Microsoft Word

Vulnerability identifier: #VU15547

Vulnerability risk: Critical

CVSSv4.0: 8.4 [CVSS:4.0/AV:L/AC:L/AT:N/PR:N/UI:A/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:A/U:Red]

CVE-ID: N/A

CWE-ID: CWE-20

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Microsoft Office
Client/Desktop applications / Office applications
Microsoft Word
Client/Desktop applications / Office applications

Vendor: Microsoft

Description

The vulnerability allows a remote attacker to execute arbitrary code on the target system.

The weakness exists due to a logical bug is revealed when embedding a video via the 'online video' feature. A remote attacker can embed a video inside a Word document, edit the XML file named document.xml, replace the video link with a crafted payload created by the attacker which opens Internet Explorer Download Manager with the embedded code execution file and execute arbitrary code with elevated privileges.

Successful exploitation of the vulnerability may result in system compromise.

Note: as of October 31, 2018 the vulnerability is being actively exploited in the wild.

Mitigation

Vulnerable software versions

Microsoft Office: 2013, 2016, 2019

Microsoft Word: 2013, 2016

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External links
https://blog.cymulate.com/abusing-microsoft-office-online-video
https://blog.trendmicro.com/trendlabs-security-intelligence/hide-and-script-inserted-malicious-urls-...

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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?

Yes. This vulnerability is being exploited in the wild.