UBUNTU-CVE-2015-5600

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    UBUNTU-CVE-2015-5600

    Published: 2 Aug 2015Last Modified: 29 May 2026
    Upstream:
    CVE-2015-5600
    Aliases:
    USN-2710-1

    Summary:

    Details: The kbdint_next_device function in auth2-chall.c in sshd in OpenSSH through 6.9 does not properly restrict the processing of keyboard-interactive devices within a single connection, which makes it easier for remote attackers to conduct brute-force attacks or cause a denial of service (CPU consumption) via a long and duplicative list in the ssh -oKbdInteractiveDevices option, as demonstrated by a modified client that provides a different password for each pam element on this list.

    References: https://ubuntu.com/security/CVE-2015-5600, http://seclists.org/fulldisclosure/2015/Jul/92, https://kingcope.wordpress.com/2015/07/16/openssh-keyboard-interactive-authentication-brute-force-vulnerability-maxauthtries-bypass/, https://ubuntu.com/security/notices/USN-2710-1, https://www.cve.org/CVERecord?id=CVE-2015-5600

    Affected packages

    Package

    Name: openssh

    Purl: pkg:deb/ubuntu/openssh?arch=source&distro=trusty

    Affected ranges

    Type: ECOSYSTEM

    Events:

    Introduced- 0
    Fixed -1:6.6p1-2ubuntu2.2

    Affected versions

    1:6.2p2-6

    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