title: BuildKit possible host system access from mount stub cleaner
description: BuildKit is a toolkit for converting source code to build artifacts in an efficient, expressive and repeatable manner. A malicious BuildKit frontend or Dockerfile using RUN --mount could trick the feature that removes empty files created for the mountpoints into removing a file outside the container, from the host system. The issue has been fixed in v0.12.5. Workarounds include avoiding using BuildKit frontends from an untrusted source or building an untrusted Dockerfile containing RUN --mount feature.
problem types: CWE-22: Improper Limitation of a Pathname to a Restricted Directory ('Path Traversal')
affected:
{
vendor: moby
product: buildkit
versions:
version: < 0.12.5, status: affected
}
metrics:
cvssV3_1: [
attackComplexity: LOW
attackVector: NETWORK
availabilityImpact: HIGH
baseScore: 10
baseSeverity: CRITICAL
confidentialityImpact: NONE
integrityImpact: HIGH
privilegesRequired: NONE
scope: CHANGED
userInteraction: NONE
vectorString: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:H/A:H
version: 3.1
]