BuildKit is a toolkit for converting source code to build artifacts in an efficient, expressive and repeatable manner. Prior to 0.31.2, a custom client can produce such an upload request to the BuildKit daemon that files can escape from the BuildKit-controlled state directory. The client needs to have valid permissions to access BuildKit control API to issue builds, eg., bypass authentication, etc. This issue is fixed in version 0.31.2.
Impact A custom frontend could send a crafted build request that disabled Seccomp and AppArmor protections for the build container, even if the user did not explicitly allow the security.insecure entitlement. Other security measures, like Linux capabilities were still applied to these containers.
Patches Problem has been fixed in versions v0.31.1+
Workarounds Only use BuildKit frontends from trusted providers.
BuildKit is a toolkit for converting source code to build artifacts in an efficient, expressive and repeatable manner. Prior to version 0.28.1, when using a custom BuildKit frontend, the frontend can craft an API message that causes files to be written outside of the BuildKit state directory for the execution context. The issue has been fixed in v0.28.1. The vulnerability requires using an untrusted BuildKit frontend set with #syntax or --build-arg BUILDKITSYNTAX. Using these options with a well-known frontend image like docker/dockerfile is not affected.
A malicious BuildKit client or frontend could craft a request that could lead to BuildKit daemon crashing with a panic.
BuildKit is a toolkit for converting source code to build artifacts in an efficient, expressive and repeatable manner. Prior to version 0.28.1, insufficient validation of Git URL fragment subdir components may allow access to files outside the checked-out Git repository root. Possible access is limited to files on the same mounted filesystem. The issue has been fixed in version v0.28.1 The issue affects only builds that use Git URLs with a subpath component. As a workaround, avoid building Dockerfiles from untrusted sources or using the subdir component from an untrusted Git repository where the subdir component could point to a symlink.