SB2016081006 - Escalation of privileges in Kerberos and NetLogon implementation in Microsoft Windows
Published: August 10, 2016
Breakdown by Severity
- Low
- Medium
- High
- Critical
Description
This security bulletin contains information about 2 vulnerabilities.
1) Kerberos privilege escalation (CVE-ID: CVE-2016-3237)
CWE-ID: CWE-255 - Credentials Management
CVSSv4: CVSS:4.0/AV:A/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:P/U:Green
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)
CWE-ID: CWE-255 - Credentials Management
CVSSv4: CVSS:4.0/AV:L/AC:L/AT:N/PR:L/UI:N/VC:L/VI:L/VA:L/SC:N/SI:N/SA:N/E:U/U:Clear
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.