CVE-2019-5736 is a high-severity (CVSS 8.6) OS Command Injection vulnerability. 25 public exploit references exist, so weaponization risk is real. A fix is available — see the affected versions and patch details below.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
CVE-2019-5736 by exploitation likelihood (EPSS) against impact (CVSS). In the shaded patch-first corner (EPSS 50%+, CVSS 7.0+).
Where this sits among everything scored
Of 396,966 CVEs with a current EPSS score, this one falls in the ≥ 90% band (highlighted). Counts from FIRST.org, log-scaled.
Description
runc through 1.0-rc6, as used in Docker before 18.09.2 and other products, allows attackers to overwrite the host runc binary (and consequently obtain host root access) by leveraging the ability to execute a command as root within one of these types of containers: (1) a new container with an attacker-controlled image, or (2) an existing container, to which the attacker previously had write access, that can be attached with docker exec. This occurs because of file-descriptor mishandling, related to /proc/self/exe.
Affected Products
mesosapacheubuntu linuxcanonicaldc\/osd2iqkubernetes engined2iqdockerdockerfedorafedoraprojectResearch use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
runc < 1.0-rc6 (Docker < 18.09.2) - Container Breakout (1)
by feexd · Feb 12, 2019
runc < 1.0-rc6 (Docker < 18.09.2) - Container Breakout (2)
by embargo · Feb 13, 2019
Detection & mitigation playbook
VulnerabilityDetect
Identify every host running the affected component and compare the installed build against the fixed version below — for source-built or distro-packaged software the version string, not a lockfile, is the source of truth (`dpkg -l`, `rpm -q`, or the binary's own `--version`).
Fix
Upgrade the affected component to the fixed release for CVE-2019-5736, or apply your distribution's backported patch — distro builds are often patched at an older version number, so check your vendor's advisory rather than the upstream version alone.
Workarounds
Stop passing untrusted input into the interpreter or shell: call the affected binary with an argument array rather than a composed command string, reject anything outside a strict allowlist of expected values, and run the component under an account that cannot reach beyond the work it legitimately does.
Fixing This On Your OS
If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.
The 'docker' package shipped in Red Hat Enterprise Linux 7 Extras bundles 'runc' since 'docker' starting from version 1.12. Both the 'docker' and 'runc' packages are affected by this issue. The 'docker-latest' package is deprecated as of Red Hat Enterprise Linux 7.5. Customers using this package should update to the…
This vulnerability is mitigated on Red Hat Enterprise Linux 7 if SELinux is in enforcing mode. SELinux in enforcing mode is a pre-requisite for OpenShift Container Platform 3.x.Source: Red Hat security advisory for CVE-2019-5736 (CC BY 4.0)
| Product | Fixed in | Advisory |
|---|---|---|
| Other | see advisory | RHSA-2019:0401 |
| Red Hat Enterprise Linux 7 Extras | runc-0:1.0.0-59.dev.git2abd837.el7 | RHSA-2019:0303 |
| Red Hat Enterprise Linux 7 Extras | docker-2:1.13.1-91.git07f3374.el7 | RHSA-2019:0304 |
| Red Hat Enterprise Linux 8 | container-tools:rhel8-8000020190416221845.2ffa3d27 | RHSA-2019:0975 |
| Red Hat OpenShift Container Platform 3.4 | docker-2:1.12.6-79.git5680db5.el7 | RHSA-2019:0408 |
Frequently Asked Questions
Is CVE-2019-5736 in your dependencies?
Find it across , including transitive dependencies.