Description: Exploitation of vulnerabilities in the host kernel's interaction with Firecracker, specifically through vhost-net, vsock, or by bypassing seccomp restrictions.
Firecracker Contribution: Firecracker directly relies on the host kernel for these functionalities, making kernel vulnerabilities directly exploitable through Firecracker.
Example: A compromised guest sends crafted network packets to exploit a vhost-net vulnerability, or uses a seccomp bypass to execute arbitrary system calls on the host.
Impact: Host system compromise, denial of service, data leakage.
Risk Severity: Critical to High.
Mitigation Strategies:
* Developers: Minimize guest interaction with vulnerable kernel features. Contribute to upstream kernel security.
* Users: Keep the host kernel updated. Use a hardened kernel. Employ strict network isolation (namespaces, firewalls). Audit and refine seccomp profiles rigorously. Monitor kernel events.
Attack Surface: Firecracker API and MMDS Attacks
Description: Attacks targeting the Firecracker API server or the Metadata Service (MMDS) to gain unauthorized control or inject malicious data. Firecracker Contribution: The API and MMDS are core components of Firecracker, providing essential management and configuration capabilities. Vulnerabilities here directly impact Firecracker's security. Example: An attacker exploits a command injection in the API to launch a privileged microVM, or compromises the MMDS to inject malicious boot scripts. Impact: Complete control over Firecracker instances, guest VM compromise, data exfiltration, denial of service. Risk Severity: Critical. Mitigation Strategies: * Developers: Implement robust authentication/authorization for the API. Use secure coding practices. Validate all MMDS data within the guest. * Users: Secure the API server (strong authentication, TLS). Restrict network access to the API and MMDS. Use a reverse proxy. Monitor API access logs.
Attack Surface: Virtio Device Emulation Vulnerabilities
Description: Exploitation of bugs in Firecracker's own implementation of virtio device emulation. Firecracker Contribution: Firecracker directly implements virtio device emulation. This is not a reliance on an external component (like the kernel for networking), but an internal code path. Example: A compromised guest sends a malformed request to the virtio block device, causing a denial-of-service or potentially triggering a more severe vulnerability within Firecracker. Impact: Denial of service, potential host code execution (rare but possible), data corruption. Risk Severity: High to Critical. Mitigation Strategies: * Developers: Thoroughly fuzz test and audit the virtio device emulation code. Follow secure coding practices. * Users: Keep Firecracker updated. Monitor Firecracker's resource usage and logs. Minimize exposed virtio devices.
Attack Surface: Jailer Misconfiguration/Vulnerabilities
Description: Weaknesses or misconfigurations in the Jailer process, which Firecracker uses for its own containment. Firecracker Contribution: Firecracker integrates and depends on Jailer for its security model. A flaw in Jailer directly weakens Firecracker's isolation. Example: A misconfigured Jailer allows Firecracker to access files outside its intended chroot, leading to information disclosure or potential privilege escalation. Impact: Weakened isolation, potential host compromise, information disclosure. Risk Severity: High. Mitigation Strategies: * Developers: Test and audit Jailer configurations. Contribute to Jailer security. * Users: Carefully review and validate Jailer configurations. Keep Jailer updated. Monitor Jailer-related behavior. Use minimal capabilities.