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    CVE-2005-2531

    OpenVPN before 2.0.1, when running with "verb 0" and without TLS authentication, does not properly flush the OpenSSL error queue when a client fails certificate authentication to the server and causes the error to be processed by the wrong client, which allows remote attackers to cause a denial of service (client disconnection) via a large number of failed authentication attempts.

    Published:Aug 24, 2005
    Last Modified:Apr 16, 2026
    EPS:Aug 24, 2005
    EPSS Score:0.0141
    CVSS Score:5

    Affected Products

    Vendor
    Openvpn
    Product
    Openvpn

    Exploits

    No exploit reference

    Common Weakness Enumeration

    No CWE recorded yet

    Common Attack Pattern Enumeration and Classification (CAPEC)

    No CAPEC recorded yet

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    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