CVE-2022-27651

The Dangerous Inheritance: How CVE-2022-27651 Broke Container Least Privilege

Alon Barad
Alon Barad
Software Engineer

Jan 2, 2026·5 min read·0 visits

Executive Summary (TL;DR)

Buildah and Docker Engine (Moby) were initializing containers with a fully populated 'Inheritable' capability set. This violated the principle of least privilege, allowing processes within the container to easily elevate their privileges to the container's maximum bounding set simply by executing binaries with file capabilities set. It's a classic case of "default insecure" configuration.

A deep dive into a subtle but significant flaw in how Buildah and Docker Engine initialized Linux process capabilities. By misconfiguring the Inheritable set, these runtimes allowed unintended privilege escalation within containers, turning the complex mathematics of Linux permissions against the security model.

Fix Analysis (1)

Technical Appendix

CVSS Score
6.8/ 10
CVSS:3.1/AV:L/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:N
EPSS Probability
0.13%
Top 100% most exploited

Affected Systems

Buildah (versions <= 1.24.0)Moby / Docker Engine (versions < 20.10.9)Podman (via Buildah dependency)

Affected Versions Detail

Product
Affected Versions
Fixed Version
Buildah
Containers
<= 1.24.01.25.0
Moby (Docker)
Moby Project
< 20.10.920.10.9
AttributeDetail
CWE IDCWE-276
Attack VectorLocal (Container)
CVSS6.8 (Medium)
ImpactPrivilege Escalation (Intra-Container)
Exploit StatusPoC Available
Vulnerable ComponentOCI Runtime Spec Generation
CWE-276
Incorrect Default Permissions

Incorrect Default Permissions

Vulnerability Timeline

CVE Published
2022-04-04
Patch Committed (Buildah)
2022-03-23
Advisory Released
2022-04-04

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