NULL dereference when processing SMB traffic in Microsoft Windows

1) NULL pointer dereference

EUVDB-ID: #VU5610

Risk: Medium

CVSSv3.1: 9.3 [CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:H/I:H/A:H/E:F/RL:O/RC:C]

CVE-ID: CVE-2017-0016

CWE-ID: CWE-476 - NULL Pointer Dereference

Exploit availability: No

Description

The vulnerability allows a remote attacker to cause denial of service.

The vulnerability exists due to a NULL pointer dereference error when processing Server Message Block (SMB) network traffic. A remote attacker can send specially crafted response, containing too many bytes following the structure defined in the SMB2 TREE_CONNECT Response structure and cause the affected system to crash.

Successful exploitation of the vulnerability may allow an attacker to perform a denial of service (DoS) attack.

Note: the exploit code for this vulnerability is publicly available.

Mitigation

Install updates from vendor's website.

Vulnerable software versions

Windows: 8.1 - 10

Windows Server: 2012 - 2016

External links

http://www.kb.cert.org/vuls/id/867968 
http://github.com/lgandx/PoC/tree/master/SMBv3%20Tree%20Connect
http://technet.microsoft.com/en-us/library/security/MS17-012

Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote non-authenticated attacker via the Internet.

Is there known malware, which exploits this vulnerability?

No. We are not aware of malware exploiting this vulnerability. However, a fully functional exploit for this vulnerability is available.