Main Vulnerability Database Vulnerabilities #VU6544

Denial of service in OpenVPN for Windows - CVE-2017-7478

Published: May 15, 2017 / Updated: September 14, 2018

Vulnerability identifier: #VU6544

CSH Severity: Medium

CVSS v4: 7.1 [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]

CVE-ID: CVE-2017-7478

CWE-ID: CWE-20

Exploitation vector: Remote access

Exploit availability: Public exploit is available

Vulnerability details

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 send a specially crafted P_CONTROL packet and cause the OpenVPN server process to stop running due to an ASSERT() exception.

Successful exploitation of the vulnerability results in denial of service.

Affected software

OpenVPN for Windows
openvpn (Alpine package)
openvpn
Fedora
SUSE Linux
Ubuntu

How to mitigate CVE-2017-7478

Update to version 2.3.15, 2.4.2 or later.

openvpn (Alpine package) - update to 2.3.15-r0
openvpn - addressed in versions 2.3.16-1.fc24, 2.4.2-1.el6, 2.4.2-1.fc25, 2.4.2-1.fc26, 2.4.2-2.el7, 2.4.3-1.el6

Links to Public Exploits and PoC-codes

Exploit #1181 - OpenVPN 2.4.0 - Unauthenticated Denial of Service (March 18, 2020)

External References

http://community.openvpn.net/openvpn/wiki/QuarkslabAndCryptographyEngineerAudits