OpenVPN 2024 is a robust and highly flexible VPN daemon. OpenVPN supports SSL/TLS security, ethernet bridging, TCP or UDP tunnel transport through proxies or NAT, support for dynamic IP addresses and DHCP, scalability to hundreds or thousands of users, and portability to most major OS platforms.
OpenVPN is tightly bound to the OpenSSL library, and derives much of its crypto capabilities from it.
OpenVPN supports conventional encryption using a pre-shared secret key (Static Key mode) or public key security (SSL/TLS mode) using client & server certificates. OpenVPN also supports non-encrypted TCP/UDP tunnels.
OpenVPN is designed to work with the TUN/TAP virtual networking interface that exists on most platforms.
Overall, OpenVPN aims to offer many of the key features of IPSec but with a relatively lightweight footprint.
What can I use OpenVPN for?
- Tunnel any IP subnetwork or virtual ethernet adapter over a single UDP or TCP port,
- Configure a scalable, load-balanced VPN server farm using one or more machines which can handle thousands of dynamic connections from incoming VPN clients,
- Use all of the encryption, authentication, and certification features of the OpenSSL library to protect your private network traffic as it transits the internet,
- Use any cipher, key size, or HMAC digest (for datagram integrity checking) supported by the OpenSSL library,
- Choose between static-key based conventional encryption or certificate-based public key encryption,
- Use static, pre-shared keys or TLS-based dynamic key exchange,
- Use real-time adaptive link compression and traffic-shaping to manage link bandwidth utilization,
- Tunnel networks whose public endpoints are dynamic such as DHCP or dial-in clients,
- Tunnel networks through connection-oriented stateful firewalls without having to use explicit firewall rules,
- Tunnel networks over NAT,
- Create secure ethernet bridges using virtual tap devices, and
- Control OpenVPN using a GUI on Windows or Mac OS X.
How do I set up OpenVPN?
- Download OpenVPN for your operating system
- Execute the download file to install the client on your computer
- Input url for OpenVPN server or drag and drop config file (you can try VPNBook)
What is the difference between OpenVPN and OpenVPN Connect?
OpenVPN is open source, completely free, and supported by the community. OpenVPN Connect is the commercial implementation of OpenVPN. OpenVPN Connect has a free version but this version is limited to two connections. Both have a similar GUI.
Is OpenVPN free?
Yes, OpenVPN is free and open source. It does require some configuring, but ultimately it has no cost for the user.
What's New
Security fixes:
- CVE-2024-4877: Windows: harden interactive service pipe. Security scope: a malicious process with "some" elevated privileges (SeImpersonatePrivilege) could open the pipe a second time, tricking openvn GUI into providing user credentials (tokens), getting full access to the account openvpn-gui.exe runs as. (Zeze with TeamT5)
- CVE-2024-5594: control channel: refuse control channel messages with nonprintable characters in them. Security scope: a malicious openvpn peer can send garbage to openvpn log, or cause high CPU load. (Reynir Björnsson)
- CVE-2024-28882: only call schedule_exit() once (on a given peer). Security scope: an authenticated client can make the server "keep the session" even when the server has been told to disconnect this client (Reynir Björnsson)
New features:
- Windows Crypto-API: Implement Windows CA template match for searching certificates in windows crypto store.
- Support pre-created DCO interface on FreeBSD (OpenVPN would fail to set ifmode p2p/subnet otherwise)
Bug fixes:
- Fix connect timeout when using SOCKS proxies (trac #328, github #267)
- Work around LibreSSL crashing on OpenBSD 7.5 when enumerating ciphers (LibreSSL bug, already fixed upstream, but not backported to OpenBSD 7.5, see also LibreSSL/OpenBSD#150)
- Add bracket in fingerprint message and do not warn about missing verification (github #516)
Documentation:
- Remove "experimental" denotation for --fast-io
- Correctly document ifconfig_* variables passed to scripts
- Documentation: make section levels consistent
- Samples: Update sample configurations (remove compression & old cipher settings, add more informative comments)
Windows MSI changes since 2.6.10:
- For the Windows-specific security fixes see above
- Built against OpenSSL 3.3.1
- Included openvpn-gui updated to 11.49.0.0
- Contains part of the fix for CVE-2024-4877