CVE-2019-13139 - Docker build code execution

Earlier in the year, while doing some research for my talk at Troopers 2019, in which I examined build systems and the how git can cause security issues, I found a git related vulnerability in Docker. This vulnerability has since been assigned CVE-2019-13139 and was patched in the Docker engine update 18.09.4. The issue is a relative straight forward command injection, however, what possibly makes it a little more interesting is that it occurs in a Go code base....

July 16, 2019 · 8 min · 1662 words · Etienne Stalmans

Bypassing Docker Authz Plugin and Using Docker-Containerd for Privesc

Containers, Docker containers in particular, are deployed everywhere these days. This is especially true in build environments or your typical CI/CD pipeline. A frequent requirement in these environments is the ability to build Docker container images, which tends to introduce security vulnerabilities through misconfiguration. One typically finds that the docker daemon is exposed to allow for so-called docker-in-docker builds, which I’ve previously shown can easily lead to container breakout. This means I’m always on the lookout for possible places that the Docker daemon/API might be directly accessible....

July 11, 2019 · 13 min · 2581 words · Etienne Stalmans