SB2016081006 - Escalation of privileges in Kerberos and NetLogon implementation in Microsoft Windows

Description

This security bulletin contains information about 2 secuirty vulnerabilities.

1) Kerberos privilege escalation (CVE-ID: CVE-2016-3237)

The vulnerability allows an attacker with access to local network to gain elevated privileges.

The vulnerability exists in Kerberos implementation when handling password change request. A local attacker can make the operating system to fall back to NT LAN Manager (NTLM) Authentication Protocol as the default authentication protocol.

Successful exploitation of this vulnerability will allow a local attacker to launch a man-in-the-middle (MiTM) attack against the traffic passing between a domain controller and the target machine, intercept and decrypt credentials during password change request.

2) Netlogon privilege escalation (CVE-ID: CVE-2016-3300)

The vulnerability allows a local user gain elevated privileges on vulnerable system.

The vulnerability exists due to Windows Netlogon service incorrectly handles secure communication to a domain controller. A local attacker can run arbitrary code on the vulnerable system with elevated privileges.

Successful exploitation of this vulnerability will allow a local user to elevate privileges on the system, joined to Windows Server 2012 or Windows Server 2012 R2 domain controller.

Remediation

Install update from vendor's website.

References

• https://technet.microsoft.com/en-us/library/security/ms16-101.aspx