#VU6545 Denial of service in OpenVPN for Windows - CVE-2017-7479

Vulnerability identifier: #VU6545

Vulnerability risk: Medium

CVSSv4.0: 4.9 [CVSS:4.0/AV:N/AC:L/AT:N/PR:L/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N/E:U/U:Green]

CVE-ID: CVE-2017-7479

CWE-ID: CWE-20

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 authenticated attacker to cause DoS conditions on the target system.

The weakness exists due to improper user-input validation. A remote attacker can cause the packet-IDs on the target server to be consumed, trigger the server process to hit an ASSERT() and stop running.

Successful exploitation of the vulnerability of results in denial of service.

Mitigation
Update to version 2.3.15, 2.4.2 or later.

Vulnerable software versions

OpenVPN for Windows: 2.3.12 - 2.3.14, 2.4.0 - 2.4.1

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External links
https://community.openvpn.net/openvpn/wiki/QuarkslabAndCryptographyEngineerAudits

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Q & A

Can this vulnerability be exploited remotely?

Yes. This vulnerability can be exploited by a remote authenticated user via the Internet.

Is there known malware, which exploits this vulnerability?

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