OpenVPN Authentication Bypass Vulnerability - CVE-2020-15078
Summary
ALPINE-CVE-2020-15078: OpenVPN 2.5.1 and earlier versions allows a remote attackers to bypass authentication and access control channel data on servers configured with deferred authentication, which can be used to potentially trigger further i... Affects openvpn versions < 2.4.11-r0. Fixed in 2.4.11-r0. How to fix ↓
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Background
OpenVPN is a widely used open-source software that enables secure point-to-point or site-to-site connections in routed or bridged configurations. It is known for its flexibility, security, and ability to traverse NAT and firewalls. However, versions 2.5.1 and earlier are vulnerable to an authentication bypass issue that can compromise the security of the connection.
Vulnerability Detail
The vulnerability, identified as CVE-2020-15078, allows remote attackers to bypass authentication and access control channel data on servers configured with deferred authentication. This flaw can lead to unauthorized access and potential information leaks, posing significant risks to the confidentiality of sensitive data transmitted over the VPN.
How To Fix
Minimum fixed version
2.4.11-r0
This is the first release that contains the fix.
sudo apk add --upgrade openvpnTip — Not sure which version your app runs? Vulert can match this fix to it. Scan free →
Workaround
As a temporary workaround, consider disabling deferred authentication on your OpenVPN server configuration until the software can be updated. This can be done by modifying the server configuration file to ensure that authentication is enforced immediately.
Conclusion
The OpenVPN authentication bypass vulnerability (CVE-2020-15078) poses a significant risk to users of versions 2.5.1 and earlier. It is essential to update to the latest patched version to safeguard against unauthorized access and potential data leaks. Users are encouraged to check their systems for vulnerabilities using tools like Vulert.
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FAQ
CVE-2020-15078 is a vulnerability in OpenVPN that allows remote attackers to bypass authentication on servers configured with deferred authentication.
OpenVPN versions 2.5.1 and earlier are affected by this vulnerability.
You can use Vulert's playground at Vulert Scanner to check if your application is affected by this vulnerability without requiring any signup.
The CVSS score of CVE-2020-15078 is 7.5, indicating a high severity level.
If immediate updates are not possible, consider disabling deferred authentication as a temporary workaround to mitigate the risk.
References
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