#VU8637 Buffer overflow in OpenVPN for Windows - CVE-2017-12166

Vulnerability identifier: #VU8637

Vulnerability risk: High

CVSSv4.0: 8.1 [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:U/U:Amber]

CVE-ID: CVE-2017-12166

CWE-ID: CWE-119

Exploitation vector: Network

Exploit availability: No

Vulnerable software:
OpenVPN for Windows
Client/Desktop applications / Software for system administration

Vendor: OpenVPN

Description

The vulnerability allows a remote attacker to execute arbitrary code on the target system.

The vulnerability exists due to boundary error in the read_key() function when "Key Method 1" is used. A remote unauthenticated attacker can send a specially crafted key, trigger buffer overflow and cause denial of service or execute arbitrary code on the target system.

Successful exploitation of this vulnerability may result in complete compromise of vulnerable system.

Mitigation
Update to version 2.4.4 or 2.3.18.

Vulnerable software versions

OpenVPN for Windows: 2.3.0 - 2.3.17, 2.4.0 - 2.4.3

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External links
https://community.openvpn.net/openvpn/wiki/CVE-2017-12166

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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.