Tag: Linux

I recently came across an exceptionally dense technical analysis about container security that’s worth sharing. The author started with a simple hypothesis: container filesystem isolation should be sufficient for multi-tenant workloads without virtual machines, if you sufficiently understand what’s happening at the syscall level.

After thorough investigation, the conclusion is more uncomfortable than expected: the defaults protect you well, but the moment you reach for “advanced” features like bidirectional mount propagation or SELinux relabeling, you’re one misconfiguration away from handing an attacker the keys to your host.

Sometimes we may need to update the public keys of some Ubuntu repositories. A symptom is the following error: