Subject: [ASA-202004-16] openvpn: denial of service Arch Linux Security Advisory ASA-202004-16 ========================================== Severity: Medium Date : 2020-04-17 CVE-ID : CVE-2020-11810 Package : openvpn Type : denial of service Remote : Yes Link : https://security.archlinux.org/AVG-1135 Summary ======= The package openvpn before version 2.4.9-1 is vulnerable to denial of service. Resolution ========== Upgrade to 2.4.9-1. # pacman -Syu "openvpn>=2.4.9-1" The problem has been fixed upstream in version 2.4.9. Workaround ========== None. Description =========== A security issue has been found in OpenVPN before 2.4.9, where a 'peer- id' check is not performed correctly during a small amount of time after a connection has been established. A rogue client sending a data channel packet during that time, from a different source address and with the same 'peer-id', would cause the client data to float to that new address, effectively sopping the VPN traffic of the first, legitimate client. Impact ====== A remote attacker might be able to cause the legitimate VPN session of another client to stall, by sending a crafted packet right at the beginning of the VPN session. References ========== https://github.com/OpenVPN/openvpn/commit/37bc691e7d26ea4eb61a8a434ebd7a9ae76225ab https://community.openvpn.net/openvpn/ticket/1272 https://security.archlinux.org/CVE-2020-11810