CVE-2006-2229 in OpenVPN
Summary
by MITRE
OpenVPN 2.0.7 and earlier, when configured to use the --management option with an IP that is not 127.0.0.1, uses a cleartext password for TCP sessions to the management interface, which might allow remote attackers to view sensitive information or cause a denial of service.
If you want to get best quality of vulnerability data, you may have to visit VulDB.
Analysis
by VulDB Data Team • 06/17/2019
The vulnerability identified as CVE-2006-2229 affects OpenVPN versions 2.0.7 and earlier when configured with the --management option using a non-local IP address. This flaw represents a significant security weakness in the management interface implementation that could be exploited by remote attackers to gain unauthorized access to sensitive information or disrupt service availability. The issue stems from the improper handling of authentication credentials when the management interface is exposed beyond the local loopback address.
The technical implementation flaw occurs within the OpenVPN management interface protocol where cleartext passwords are transmitted over TCP connections when the management IP address is configured to anything other than 127.0.0.1. This design decision violates fundamental security principles by failing to implement proper authentication mechanisms for remote management sessions. The vulnerability specifically affects the TCP session establishment process where authentication credentials are sent in plain text format, making them susceptible to interception and replay attacks. This weakness is classified under CWE-312, which deals with cleartext storage of sensitive information, and more specifically addresses CWE-522, which covers insufficiently protected credentials.
The operational impact of this vulnerability extends beyond simple information disclosure to encompass potential denial of service conditions and unauthorized administrative access. Remote attackers who can establish TCP connections to the management interface can potentially view sensitive operational data including configuration parameters, connection statistics, and other management information. The cleartext transmission of passwords creates an avenue for credential theft, which could lead to full administrative control over the OpenVPN server. This vulnerability particularly affects deployments where OpenVPN management interfaces are exposed to untrusted networks or external administrative access points, creating a direct pathway for attackers to compromise the entire VPN infrastructure.
The security implications of this vulnerability align with several ATT&CK tactics including T1078 for valid accounts and T1566 for credential harvesting. Organizations utilizing OpenVPN with remote management capabilities are at risk of unauthorized access to their network infrastructure, potentially leading to data breaches or service disruption. The vulnerability demonstrates a critical oversight in the design of network management interfaces where remote access security considerations were not adequately addressed. This flaw underscores the importance of implementing proper authentication mechanisms and secure communication protocols for all administrative interfaces, regardless of their exposure scope.
Mitigation strategies for CVE-2006-2229 should prioritize immediate patching to versions of OpenVPN that address this specific vulnerability. Administrators should ensure that the --management option is either configured to use 127.0.0.1 or that proper network segmentation is implemented to restrict access to the management interface. Network administrators should also consider implementing additional security controls such as firewall rules to limit access to management ports, use of SSH tunneling for remote management access, and implementation of more secure authentication mechanisms. The vulnerability highlights the critical need for regular security assessments of network infrastructure components and the importance of maintaining up-to-date software versions to protect against known security flaws. Organizations should also implement monitoring solutions to detect unauthorized access attempts to management interfaces and establish proper incident response procedures to address potential exploitation of this vulnerability.