NULL dereference when processing SMB traffic in Microsoft Windows

1) NULL pointer dereference

EUVDB-ID: #VU5610

Risk: Medium

CVSSv4.0: 9.3 [CVSS:4.0/AV:N/AC:L/AT:N/PR:N/UI:N/VC:H/VI:H/VA:H/SC:N/SI:N/SA:N/E:A/U:Green]

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 R2 - 2016 10.0.14393.10

CPE2.3

• cpe:2.3:o:microsoft:windows:8.1:*:*:*:*:*:*:*
• cpe:2.3:o:microsoft:windows:*:*:*:*:*:*:*:*
• cpe:2.3:o:microsoft:windows_server:*:*:*:*:*:*:*:*
• cpe:2.3:o:microsoft:windows_server:2016:10.0.14393.10:*:*:*:*:*:*

External links

https://www.kb.cert.org/vuls/id/867968 
https://github.com/lgandx/PoC/tree/master/SMBv3%20Tree%20Connect
https://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.