Vulnerability identifier: #VU8757

Vulnerability risk: Low

CVSSv3.1: 5.5 [CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L/E:U/RL:O/RC:C]

CVE-ID: CVE-2017-11786

CWE-ID: CWE-264

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
Skype for Business
Client/Desktop applications / Messaging software

Vendor: Microsoft

Description
The vulnerability allows a remote authenticated attacker to gain elevated privileges on the target system.

The weakness exists due to when Skype for Business fails to properly handle specific authentication requests. A remote attacker can invite a user to an instant message session while using a malicious profile image, steal an authentication has and gain system privileges.

Mitigation
Install updates from vendor's website.

Vulnerable software versions

Skype for Business: 2016

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External links
http://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2017-11786

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Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote authenticated user via the Internet.

Is there known malware, which exploits this vulnerability?

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