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CVE-2021-21284

CVE-2021-21284 · privilege escalation in Moby

This page contains facts from public vulnerability sources. Check the original advisory before updating.

In Docker before versions 9.03.15, 20.10.3 there is a vulnerability involving the --userns-remap option in which access to remapped root allows privilege escalation to real root. When using "--userns-remap", if the root user in the remapped namespace has access to the host filesystem they can modify files under "/var/lib/docker/<remapping>" that cause writing files with extended privileges. Versions 20.10.3 and 19.03.15 contain patches that prevent privilege escalation from remapped user.

CVSS 6.8 · Medium · EPSS 1.1% · Fix available

Published
Updated

Stack: system · containers

Affected products and versions

  • docker engine

    Versions
    • < 19.03.15: Affected
    • >= 20.0.0, < 20.10.3: Affected

    No fix published

  • docker.io Debian:12

    Affected ranges
    • ECOSYSTEM: < 20.10.3+dfsg1-1

    Update to 20.10.3+dfsg1-1

  • docker.io Debian:13

    Affected ranges
    • ECOSYSTEM: < 20.10.3+dfsg1-1

    Update to 20.10.3+dfsg1-1

  • docker.io Debian:14

    Affected ranges
    • ECOSYSTEM: < 20.10.3+dfsg1-1

    Update to 20.10.3+dfsg1-1

  • docker.io Ubuntu:Pro:16.04:LTS

    Versions
    • 1.6.2~dfsg1-1ubuntu4
    • 1.10.2-0ubuntu3
    • 1.10.2-0ubuntu4
    • 1.10.3-0ubuntu1
    • 1.10.3-0ubuntu4
    • 1.10.3-0ubuntu5
    • 1.10.3-0ubuntu6
    • 1.11.2-0ubuntu5~16.04
    • 1.12.1-0ubuntu13~16.04.1
    • 1.12.3-0ubuntu4~16.04.2
    • 1.12.6-0ubuntu1~16.04.1
    • 1.13.1-0ubuntu1~16.04.2
    • 17.03.2-0ubuntu2~16.04.1
    • 18.06.1-0ubuntu1~16.04.2
    • 18.06.1-0ubuntu1.2~16.04.1
    • 18.09.2-0ubuntu1~16.04.1
    • 18.09.5-0ubuntu1~16.04.2
    • 18.09.7-0ubuntu1~16.04.1
    • 18.09.7-0ubuntu1~16.04.4
    • 18.09.7-0ubuntu1~16.04.5
    • 18.09.7-0ubuntu1~16.04.6
    • 18.09.7-0ubuntu1~16.04.7
    • 18.09.7-0ubuntu1~16.04.9+esm1
    • 18.09.7-0ubuntu1~16.04.9+esm2
    Affected ranges
    • ECOSYSTEM: (−∞, +∞)

    No fix published

  • docker.io Ubuntu:18.04:LTS

    Versions
    • 1.13.1-0ubuntu6
    • 17.03.2-0ubuntu1
    • 17.03.2-0ubuntu3
    • 17.03.2-0ubuntu5
    • 17.12.1-0ubuntu1
    • 18.06.1-0ubuntu1~18.04.1
    • 18.06.1-0ubuntu1.2~18.04.1
    • 18.09.2-0ubuntu1~18.04.1
    • 18.09.5-0ubuntu1~18.04.2
    • 18.09.7-0ubuntu1~18.04.1
    • 18.09.7-0ubuntu1~18.04.3
    • 18.09.7-0ubuntu1~18.04.4
    • 19.03.6-0ubuntu1~18.04.1
    • 19.03.6-0ubuntu1~18.04.2
    • 19.03.6-0ubuntu1~18.04.3
    • 20.10.2-0ubuntu1~18.04.2
    • 20.10.2-0ubuntu1~18.04.3
    Affected ranges
    • ECOSYSTEM: < 20.10.7-0ubuntu1~18.04.1

    Update to 20.10.7-0ubuntu1~18.04.1

  • docker.io Ubuntu:20.04:LTS

    Versions
    • 19.03.2-0ubuntu1
    • 19.03.6-0ubuntu1
    • 19.03.8-0ubuntu1
    • 19.03.8-0ubuntu1.20.04
    • 19.03.8-0ubuntu1.20.04.1
    • 19.03.8-0ubuntu1.20.04.2
    • 20.10.2-0ubuntu1~20.04.2
    • 20.10.2-0ubuntu1~20.04.3
    Affected ranges
    • ECOSYSTEM: < 20.10.7-0ubuntu1~20.04.1

    Update to 20.10.7-0ubuntu1~20.04.1

Original sources

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