CVEvulnerability

CVE-2020-11810

3.7 LOW Published 2020-04-27 Modified 2026-06-17 Official page ↗
Status
Modified
Published
2020-04-27
Last modified
2026-06-17
Assigner
[email protected]
CVSS 3.1 ([email protected])
3.7 LOW — CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:N/A:L
CVSS 2.0 ([email protected])
4.3 MEDIUM — AV:N/AC:M/Au:N/C:N/I:N/A:P
Weaknesses
CWE-362

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.

Affected configurations

• openvpn openvpn (>= 2.4.0 < 2.4.9) • debian debian linux 8.0 • debian debian linux 9.0 • debian debian linux 10.0 • fedoraproject fedora 30 • fedoraproject fedora 32

Related

Weakness · CWE (1)

  • CWE-362 Concurrent Execution using Shared Resource with Improper Synchronization weakness

References