Vulnerability identifier: #VU7453

Vulnerability risk: Low

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

CVE-ID: CVE-2017-8563

CWE-ID: CWE-287

Exploitation vector: Local network

Exploit availability: No

Vulnerable software:
Windows
Operating systems & Components / Operating system
Windows Server
Operating systems & Components / Operating system

Vendor: Microsoft

Description

The vulnerability allows a remote attacker to gain access to potentially sensitive information.

The vulnerability exists in Microsoft Windows when Kerberos falls back to NT LAN Manager (NTLM) Authentication Protocol as the default authentication protocol. A remote attacker can send specially crafted requests to domain controller and trigger the fall back to less secure authentication protocol.

Successful exploitation of the vulnerability may allow an attacker to perform a MitM attack, intercept network traffic and gain access to users’ credentials.

Mitigation
Install updates from vendor's website.

Note: To make LDAP authentication over SSL/TLS more secure, administrators need to create a LdapEnforceChannelBinding registry setting on a Domain Controller. For more information about setting this registry key, see Microsoft Knowledge Base article 4034879.

Vulnerable software versions

Windows: 8.1 - 8.1 RT, 7, 10

Windows Server: 2008 - 2016

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External links
http://portal.msrc.microsoft.com/en-US/security-guidance/advisory/CVE-2017-8563

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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 local network (LAN).

Is there known malware, which exploits this vulnerability?

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