Shellbreaking

Shellbreaking is a term used in computer security to describe the act of escaping or bypassing a restricted command shell or sandboxed runtime environment in order to obtain higher privileges, access restricted resources, or run arbitrary commands beyond the allowed scope. It applies to various environments, including restricted shells, sandboxed execution environments, containers with confinement, or jail-like environments, and is often associated with exploiting vulnerabilities, misconfigurations, or design flaws in software, operating systems, or security policies. In practice, shellbreaking is discussed primarily in the context of security research, testing, and incident analysis.

The activity is generally illegal and unethical to perform without explicit authorization from the system owner; legitimate use occurs within professional penetration testing, red team exercises, or academic research with proper consent and legal agreements. Potential effects include privilege escalation, data leakage, persistence, and broader compromise of systems. Typical defensive measures focus on reducing the attack surface: minimizing the use of weak or misconfigured restricted shells, hardening host and kernel security, implementing robust sandboxing (containers, seccomp, AppArmor/SELinux), restricting file system and PATH access, applying least privilege, and monitoring for anomalous shell activity and command invocation patterns. Because of the sensitive nature of shellbreaking, responsible disclosure and clear authorization are essential in any related activity.