OpenVPN version 2.1.0 through 2.6.20 and 2.7_alpha1 through 2.7.4 allows attackers via an off-by-one buffer write in the NTLM proxy authentication to potentially cause a crash via a crafted NTLM response from a malicious proxy server
CVSS Details
- CVSS 4.0 Base Score: 7 (HIGH)
- CVSS 4.0 Vector: (CVSS:4.0/AV:N/AC:H/AT:P/PR:N/UI:P/VC:N/VI:N/VA:H/SC:N/SI:N/SA:H/E:X/CR:X/IR:X/AR:X/MAV:X/MAC:X/MAT:X/MPR:X/MUI:X/MVC:X/MVI:X/MVA:X/MSC:X/MSI:X/MSA:X/S:X/AU:X/R:X/V:X/RE:X/U:X)
- CVSS 3.1 Base Score: 7.5
- CVSS 3.1 Vector: (CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H)
Covered by Rapid7
| Product | Vendor Advisory | Solution File | Added | Published |
|---|---|---|---|---|
| Alpine Linux | — | Upgrade openvpn | Jul 31, 2026 | Jul 30, 2026 |
| Debian | — | Upgrade openvpn | Jul 5, 2026 | Jul 5, 2026 |
| Freebsd | — | Upgrade openvpnUpgrade openvpn-devel | Jul 7, 2026 | Jul 1, 2026 |
| Ubuntu | — | Upgrade openvpn | Jul 15, 2026 | Jul 14, 2026 |
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