UBUNTU-CVE-2020-11810

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    UBUNTU-CVE-2020-11810

    Published: 27 Apr 2020Last Modified: 4 Feb 2026
    Upstream:
    CVE-2020-11810
    Aliases:
    USN-4933-1

    Summary:

    Details: 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.

    References: https://ubuntu.com/security/CVE-2020-11810, https://ubuntu.com/security/notices/USN-4933-1, https://www.cve.org/CVERecord?id=CVE-2020-11810

    Affected packages

    Package

    Name: openvpn

    Purl: pkg:deb/ubuntu/[email protected]?arch=source&distro=bionic

    Affected ranges

    Type: ECOSYSTEM

    Events:

    Introduced- 0
    Fixed -2.4.4-2ubuntu1.5

    Affected versions

    2.4.3-4ubuntu1
    2.4.4-1ubuntu1
    2.4.4-2ubuntu1
    2.4.4-2ubuntu1.1
    2.4.4-2ubuntu1.2
    2.4.4-2ubuntu1.3

    Common Vulnerability Scoring System

    Attack Vector
    Network
    Adjacent
    Local
    Physical
    Privileges Required
    None
    Low
    High
    User Interaction
    None
    Required
    Scope
    Unchanged
    Changed
    Confidentiality
    None
    Low
    High
    Integrity
    None
    Low
    High
    Availability
    None
    Low
    High
    UBUNTU-CVE-2020-11810 | CVE-DB