Affected: Bitnami: pebble

It was discovered that Canonical's Pebble service manager read-file API and the associated pebble pull command, before v1.10.2, allowed unprivileged local users to read files with root-equivalent permissions when Pebble was running as root. Fixes are also available as backports to v1.1.1, v1.4.2, and v1.7.4.

It was discovered that Canonical's Pebble service manager read-file API and the associated pebble pull command, before v1.10.2, allowed unprivileged local users to read files with root-equivalent permissions when Pebble was running as root. Fixes are also available as backports to v1.1.1, v1.4.2, and v1.7.4.

Affected: Go: github.com/canonical/pebble

### Impact

Note: "Pebble" here refers to [Canonical's service manager](https://github.com/canonical/pebble), not the [Let's Encrypt ACME test server](https://github.com/letsencrypt/pebble).

The API behind `pebble pull`, used to read files from the workload container by Juju charms, allows access from any user, instead of just admin. In Juju Kubernetes sidecar charms, Pebble and the charm run as root, so they have full access. But if another restricted unix user gains local access to the container host, they could hit the Pebble `GET /v1/files?action=read` API and would be allowed to read any file in the workload container, for example an ssh key or database password or other sensitive information. If there are ssh keys they could then potentially ssh into the workload, or if something like a database password they could log into the database.

Note that this requires local user access to the host machine. It seems unlikely that an attacker could gain this level of access in a Juju Kubernetes context, but if someone did and there's sensitive information in files accessible to Pebble, the consequences are bad.

To reproduce the issue, go back to the Pebble version in Juju 2.9 (5842ea68c9c7), do `pebble run` as root in one terminal window, then in another terminal window, as a regular user, use the `pebble pull` CLI. You will be able to pull any file as a regular user.

### Patches

The original patch is commit https://github.com/canonical/pebble/commit/cd326225b9b0be067da7d8…