CVE-2025-2704 Denial of service in OpenVPN
Remote attackers can cause denial of service in OpenVPN servers by corrupting and replaying packets during the TLS-crypt-v2 handshake.
- Exploited in the wild
- Not known
- Login needed
- Not needed
- Attackable
- Over the internet
- Victim action needed
- Not needed
- Fix
- Available
What is CVE-2025-2704?
CVE-2025-2704 is a high-severity denial of service vulnerability in OpenVPN, published on 2 Apr 2025. An attacker can exploit it over the internet without logging in, with no action from the victim.
Official description
OpenVPN version 2.6.1 through 2.6.13 in server mode using TLS-crypt-v2 allows remote attackers to trigger a denial of service by corrupting and replaying network packets in the early handshake phase
Weakness: CWE-754
Which versions are affected by CVE-2025-2704?
It affects 1 product.
Linux distribution packages (7)
openvpn SUSE:Linux Enterprise Module for Basesystem 15 SP6 | All versions | 2.6.8-150600.3.17.1 |
openvpn-dco SUSE:Linux Enterprise Module for Basesystem 15 SP6 | All versions | 2.6.8-150600.3.17.1 |
openvpn SUSE:Linux Enterprise Module for Basesystem 15 SP7 | All versions | 2.6.8-150600.3.17.1 |
openvpn-dco SUSE:Linux Enterprise Module for Basesystem 15 SP7 | All versions | 2.6.8-150600.3.17.1 |
openvpn openSUSE:Leap 15.6 | All versions | 2.6.8-150600.3.17.1 |
openvpn-dco openSUSE:Leap 15.6 | All versions | 2.6.8-150600.3.17.1 |
openvpn openSUSE:Tumbleweed | All versions | 2.6.14-1.1 |
Products include Openvpn Openvpn.
How do I fix CVE-2025-2704?
Upgrade to a fixed version.
Upgrade, then put limits on request size, rate and nesting depth so one client cannot exhaust the service. More about Denial of service.
Is CVE-2025-2704 being exploited?
There is no known exploitation of CVE-2025-2704 in the wild and no public exploit code.
Other vulnerabilities in OpenVPN
Sources
Also known as ALPINE-CVE-2025-2704, CLEANSTART-2026-EP23751, DEBIAN-CVE-2025-2704, GHSA-5gwv-2q72-gxrm, OESA-2025-1396, OESA-2025-1397 and 5 more.