Escalation of privileges in Kerberos and NetLogon implementation in Microsoft Windows

Published: 2016-08-10
Severity Medium
Patch available YES
Number of vulnerabilities 2
CVE ID CVE-2016-3237
CVE-2016-3300
CWE ID CWE-255
Exploitation vector Local network
Public exploit Public exploit code for vulnerability #1 is available.
Vulnerable software Windows Subscribe
Windows Server
Vendor Microsoft

Security Advisory

1) Kerberos privilege escalation

Severity: Medium

CVSSv3: 5 [CVSS:3.0/AV:A/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L/E:P/RL:O/RC:C] [PCI]

CVE-ID: CVE-2016-3237

CWE-ID: CWE-255 - Credentials Management

Description

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.

Vulnerable software versions

Windows: 7, 8.1, 10, RT 8.1, Vista

Windows Server: 2008, 2008 R2, 2012, 2012 R2

CPE External links

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

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote authenticated user via the local network (LAN).

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability. However, proof of concept for this vulnerability is available.

2) Netlogon privilege escalation

Severity: Low

CVSSv3: 4.6 [CVSS:3.0/AV:L/AC:L/PR:L/UI:N/S:U/C:L/I:L/A:L/E:U/RL:O/RC:C] [PCI]

CVE-ID: CVE-2016-3300

CWE-ID: CWE-255 - Credentials Management

Description

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.

Vulnerable software versions

Windows: 8.1, RT 8.1

Windows Server: 2012, 2012 R2

CPE External links

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

Q & A

Can this vulnerability be exploited remotely?

No. This vulnerability can be exploited locally. The attacker should have authentication credentials and successfully authenticate on the system.

Is there known malware, which exploits this vulnerability?

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