What’s Vulnerable › Vulnerabilities

CVE-2016-9962

• Severity: medium (CVSS 6.4 v3.0)
• Exploited in the wild: not listed in CISA KEV
• EPSS: 0.4% probability of exploitation in the next 30 days
• Public exploit or detection template: none known
• Published: 2017-01-31 · updated 2026-06-17
• Weakness: CWE-362

Description

RunC allowed additional container processes via 'runc exec' to be ptraced by the pid 1 of the container. This allows the main processes of the container, if running as root, to gain access to file-descriptors of these new processes during the initialization and can lead to container escapes or modification of runC state before the process is fully placed inside the container.

Affected products

• Docker Engine: from 1.11.0 before 1.12.6 — fixed in 1.12.6

How to fix

Upgrade to a fixed version: Docker Engine 1.12.6. Check the vendor advisory for mitigations.

References

• http://rhn.redhat.com/errata/RHSA-2017-0116.html
• http://rhn.redhat.com/errata/RHSA-2017-0123.html
• http://rhn.redhat.com/errata/RHSA-2017-0127.html
• http://seclists.org/fulldisclosure/2017/Jan/21
• http://seclists.org/fulldisclosure/2017/Jan/29
• http://www.securityfocus.com/archive/1/540001/100/0/threaded
• http://www.securityfocus.com/bid/95361
• https://access.redhat.com/security/vulnerabilities/cve-2016-9962
• https://bugzilla.suse.com/show_bug.cgi?id=1012568#c6
• https://github.com/docker/docker/releases/tag/v1.12.6
• https://github.com/opencontainers/runc/commit/50a19c6ff828c58e5dab13830bd3dacde268afe5
• https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/BQAXJMMLRU7DD2IMG47SR2K4BOFFG7FZ/

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