The openvpn_decrypt function in crypto.c in OpenVPN 2.3.0 and earlier, when running in UDP mode, allows remote attackers to obtain sensitive information via a timing attack involving an HMAC comparison function that does not run in constant time and a padding oracle attack on the CBC mode cipher.
- https://community.openvpn.net/openvpn/wiki/SecurityAnnouncement-f375aa67cc
- https://github.com/ARPSyndicate/cve-scores