CVE-2021-3602

An information disclosure flaw was found in Buildah, when building containers using chroot isolation. Running processes in container builds (e.g. Dockerfile RUN commands) can access environment variables from parent and grandparent processes. When run in a container in a CI/CD environment, environment variables may include sensitive information that was shared with the container in order to be used only by Buildah itself (e.g. container registry credentials).

An information disclosure flaw was found in Buildah, when building containers using chroot isolation. Running processes in container builds (e.g. Dockerfile RUN commands) can access environment variables from parent and grandparent processes. When run in a container in a CI/CD environment, environment variables may include sensitive information that was shared with the container in order to be used only by Buildah itself (e.g. container registry credentials).

The RunUsingChroot function unintentionally propagates environment variables from the current process to the child process.

### Impact When running processes using "chroot" isolation, the process being run can examine the environment variables of its immediate parent and grandparent processes (CVE-2021-3602). This isolation type is often used when running `buildah` in unprivileged containers, and it is often used to do so in CI/CD environments. If sensitive information is exposed to the original `buildah` process through its environment, that information will unintentionally be shared with child processes which it starts as part of handling RUN instructions or during `buildah run`. The commands that `buildah` is instructed to run can read that information if they choose to. ### Patches Users should upgrade packages, or images which contain packages, to include version 1.21.3 or later. ### Workarounds As a workaround, invoking `buildah` in a container under `env -i` to have it started with a reinitialized environment should prevent the leakage. ### For more information If you have any questions or comments about this advisory: * Open an issue in [buildah](https://github.com/containers/buildah/issues) * Email us at [the buildah general mailing list](mailto:buildah@lists.buildah.io), or [the podman security mailing list](mailto:security@lists.podman.io) if it's sensitive.

Se ha encontrado un fallo de divulgación de información en Buildah, cuando son construidos contenedores usando el aislamiento chroot. Los procesos que son ejecutados en las construcciones de contenedores (por ejemplo, los comandos RUN de Dockerfile) pueden acceder a las variables de entorno de los procesos padres y abuelos. Cuando es ejecutado en un contenedor en un entorno CI/CD, las variables de entorno pueden incluir información confidencial que fue compartida con el contenedor para ser usada sólo por el propio Buildah (por ejemplo, las credenciales del registro del contenedor)