Vulnerability Description
An issue was discovered in OpenVPN 2.4.x before 2.4.9. An attacker can inject a data channel v2 (P_DATA_V2) packet using a victim's peer-id. Normally such packets are dropped, but if this packet arrives before the data channel crypto parameters have been initialized, the victim's connection will be dropped. This requires careful timing due to the small time window (usually within a few seconds) between the victim client connection starting and the server PUSH_REPLY response back to the client. This attack will only work if Negotiable Cipher Parameters (NCP) is in use.
CVSS Score
LOW
Affected Products
| Vendor | Product | Versions |
|---|---|---|
| Openvpn | Openvpn | >= 2.4.0, < 2.4.9 |
| Debian | Debian Linux | 8.0 |
| Fedoraproject | Fedora | 30 |
Related Weaknesses (CWE)
References
- https://bugzilla.suse.com/show_bug.cgi?id=1169925Issue TrackingThird Party Advisory
- https://community.openvpn.net/openvpn/ticket/1272ExploitVendor Advisory
- https://github.com/OpenVPN/openvpn/commit/37bc691e7d26ea4eb61a8a434ebd7a9ae76225PatchThird Party Advisory
- https://lists.debian.org/debian-lts-announce/2022/05/msg00002.htmlMailing ListThird Party Advisory
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedorapro
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedorapro
- https://patchwork.openvpn.net/patch/1079/PatchVendor Advisory
- https://security-tracker.debian.org/tracker/CVE-2020-11810Third Party Advisory
- https://bugzilla.suse.com/show_bug.cgi?id=1169925Issue TrackingThird Party Advisory
- https://community.openvpn.net/openvpn/ticket/1272ExploitVendor Advisory
- https://github.com/OpenVPN/openvpn/commit/37bc691e7d26ea4eb61a8a434ebd7a9ae76225PatchThird Party Advisory
- https://lists.debian.org/debian-lts-announce/2022/05/msg00002.htmlMailing ListThird Party Advisory
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedorapro
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedorapro
- https://patchwork.openvpn.net/patch/1079/PatchVendor Advisory
FAQ
What is CVE-2020-11810?
CVE-2020-11810 is a vulnerability with a CVSS score of 3.7 (LOW). An issue was discovered in OpenVPN 2.4.x before 2.4.9. An attacker can inject a data channel v2 (P_DATA_V2) packet using a victim's peer-id. Normally such packets are dropped, but if this packet arriv...
How severe is CVE-2020-11810?
CVE-2020-11810 has been rated LOW with a CVSS base score of 3.7/10. Review the CVSS metrics above for detailed severity breakdown.
Is there a patch for CVE-2020-11810?
Check the references section above for vendor advisories and patch information. Affected products include: Openvpn Openvpn, Debian Debian Linux, Fedoraproject Fedora.