Silent Leaks: Harvesting Secrets from Shared Linux Environments

No ratings

Presented at DEF CON 33 by

Cernica Cosmin

You don’t need a kernel exploit to cross security boundaries in Linux, and all it takes is what the system already gives you. In this talk, I’ll expose a class of quiet yet dangerous vulnerabilities where common system features in multi-user Linux environments leak sensitive information between users by default. We’ll explore how standard process inspection mechanisms and insecure scripting practices in real-world infrastructures, especially those used by large hosting panel providers can expose database passwords, API tokens, internal URLs, and other secrets to unprivileged users. I’ll demonstrate how simple, legitimate system behaviors can be passively weaponized to gather intelligence, fingerprint users, and pivot across services. All without ever escalating privileges or exploiting a single bug. This talk shows how misconfigurations and design oversights can open the door to unintended visibility. Whether you're a sysadmin, penetration tester, or just someone who lives in a shell, you’ll leave with a better understanding of what your environment might be silently exposing and how to lock it down.