UBUNTU-CVE-2018-12029

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    UBUNTU-CVE-2018-12029

    Published: 17 Jun 2018Last Modified: 4 Feb 2026
    Upstream:
    CVE-2018-12029
    Aliases:
    USN-5261-1

    Summary:

    Details: A race condition in the nginx module in Phusion Passenger 3.x through 5.x before 5.3.2 allows local escalation of privileges when a non-standard passenger_instance_registry_dir with insufficiently strict permissions is configured. Replacing a file with a symlink after the file was created, but before it was chowned, leads to the target of the link being chowned via the path. Targeting sensitive files such as root's crontab file allows privilege escalation.

    References: https://ubuntu.com/security/CVE-2018-12029, https://blog.phusion.nl/2018/06/12/passenger-5-3-2-various-security-fixes/, https://blog.phusion.nl/passenger-5-3-2, https://pulsesecurity.co.nz/advisories/phusion-passenger-priv-esc, https://www.cve.org/CVERecord?id=CVE-2018-12029, https://ubuntu.com/security/notices/USN-5261-1

    Affected packages

    Package

    Name: passenger

    Purl: pkg:deb/ubuntu/[email protected]~esm1?arch=source&distro=esm-apps/xenial

    Affected ranges

    Type: ECOSYSTEM

    Events:

    Introduced- 0
    Fixed -5.0.27-2ubuntu0.1~esm1

    Affected versions

    5.0.7-3
    5.0.22-1
    5.0.22-1build1
    5.0.22-1build2
    5.0.27-2

    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