Vulnerability in Openvpn
CVE-2020-11810
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.
Vulnerability class: Race Condition
EPSS: 0.016 (73.4th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 3.7 (Low). Vector: CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L.
Affected products
- Openvpn
- Debian Debian_linux — versions 8.0, 9.0, 10.0
- Fedoraproject Fedora — versions 30, 32
- N/a — versions n/a
Weakness classification (CWE)
References
- cve@mitre.org (x_refsource_CONFIRM, Patch, Third Party Advisory)
- cve@mitre.org (Third Party Advisory, x_refsource_MISC)
- cve@mitre.org (x_refsource_CONFIRM, Third Party Advisory, Issue Tracking)
- cve@mitre.org (x_refsource_CONFIRM, Exploit, Vendor Advisory)
- cve@mitre.org (x_refsource_CONFIRM, Patch, Vendor Advisory)
- cve@mitre.org (x_refsource_FEDORA, vendor-advisory)
- cve@mitre.org (x_refsource_FEDORA, vendor-advisory)
- cve@mitre.org (mailing-list, x_refsource_MLIST, Mailing List, Third Party Advisory)
Frequently asked questions
- What is CVE-2020-11810?
- CVE-2020-11810 is a low-severity vulnerability in Openvpn, classified under Concurrent Execution using Shared Resource with Improper Synchronization (Race Condition). CVSS score: 3.7/10. Published 2020-04-27.
- How severe is CVE-2020-11810?
- Low severity. CVSS v3 base score is 3.7 out of 10.