Shell Escape in Anchore Engine

Summary

In Anchore Engine version 0.7.0, a specially crafted container image manifest, fetched from a registry, can be used to trigger a shell escape flaw in the anchore engine analyzer service during an image analysis process. The image analysis operation can only be executed by an authenticated user via a valid API request to anchore engine, or if an already added image that anchore is monitoring has its manifest altered to exploit the same flaw. A successful attack can be used to execute commands that run in the analyzer environment, with the same permissions as the user that anchore engine is run as - including access to the credentials that Engine uses to access its own database which have read-write ability, as well as access to the running engien analyzer service environment. By default Anchore Engine is released and deployed as a container where the user is non-root, but if users run Engine directly or explicitly set the user to 'root' then that level of access may be gained in the execution environment where Engine runs. This issue is fixed in version 0.7.1.