CVE-2018-7544: openvpn

Vulnerability summary

CVE-2018-7544 is a critical (CVSS 9.1) vulnerability in openvpn. EPSS estimates a 1.79% chance of exploitation in the next 30 days, higher than 77.9% of scored vulnerabilities. 1 public exploit is recorded.

Timeline

1. 16-03-2018
   PublishedVulnerability first disclosed.
2. 14-11-2024
   Last modifiedVulnerability information updated.

Description

A cross-protocol scripting issue was discovered in the management interface in OpenVPN through 2.4.5. When this interface is enabled over TCP without a password, and when no other clients are connected to this interface, attackers can execute arbitrary management commands, obtain sensitive information, or cause a denial of service (SIGTERM) by triggering XMLHttpRequest actions in a web browser. This is demonstrated by a multipart/form-data POST to http://localhost:23000 with a "signal SIGTERM" command in a TEXTAREA element. NOTE: The vendor disputes that this is a vulnerability. They state that this is the result of improper configuration of the OpenVPN instance rather than an intrinsic vulnerability, and now more explicitly warn against such configurations in both the management-interface documentation, and with a runtime warning

• CWE-134Use of Externally-Controlled Format StringThe product uses a function that accepts a format string as an argument, but the format string originates from an external source.