threat-modeling.md

Threat Model Analysis for containers/podman

Threat: Rootless Mode Bypass/Escalation

• Threat: Rootless Mode Bypass/Escalation

  • Description: An attacker exploits a vulnerability in user namespace mapping, cgroups, or other kernel features used by Podman's rootless mode. The attacker crafts a malicious container image or exploits a vulnerability in a running container to gain elevated privileges outside the container, potentially achieving root access on the host system. This bypasses the core security feature of rootless Podman.
  • Impact: Complete host system compromise. The attacker gains full control over the host, including all other containers, data, and potentially the ability to pivot to other systems on the network.
  • Affected Component: libpod (Podman's core library), user namespace implementation in the Linux kernel, cgroups implementation, container runtime (e.g., runc, crun). Directly involves Podman's core functionality and its interaction with the kernel.
  • Risk Severity: Critical
  • Mitigation Strategies:
    • Keep the host kernel and Podman updated to the latest versions.
    • Regularly audit user namespace and cgroup configurations.
    • Employ SELinux or AppArmor in enforcing mode.
    • Use minimal base images.
    • Monitor system calls and resource usage for anomalies.
    • Use dedicated, non-login user accounts for rootless containers.
    • Avoid mounting sensitive host directories.

Threat: Rootful Container Misconfiguration (Privilege Escalation)

• Threat: Rootful Container Misconfiguration (Privilege Escalation)

  • Description: If rootful containers are used (against best practices), an attacker exploits a misconfigured container running with excessive privileges (e.g., --privileged, unnecessary capabilities, or insecure host mounts). The attacker gains control inside the container and then leverages the misconfiguration, facilitated by Podman's handling of these options, to gain root access on the host.
  • Impact: Complete host system compromise.
  • Affected Component: libpod, container runtime (e.g., runc, crun), container configuration (e.g., podman run options). Directly involves how Podman interprets and enforces (or fails to enforce) security-related command-line options.
  • Risk Severity: Critical
  • Mitigation Strategies:
    • Strongly prefer rootless mode.
    • If rootful is unavoidable, use the principle of least privilege: drop unnecessary capabilities (--cap-drop).
    • Restrict host mounts; use read-only mounts (:ro).
    • Avoid --privileged unless absolutely necessary.
    • Implement container image signing and verification.
    • Use a restricted user inside the container.

Threat: Malicious Image from Untrusted Registry (Code Injection)

• Threat: Malicious Image from Untrusted Registry (Code Injection)

  • Description: An attacker publishes a malicious image. A user, using Podman, unknowingly pulls and runs this image. Podman executes the malicious code within the container. While the container should provide isolation, the initial act of pulling and running the image is facilitated by Podman.
  • Impact: Compromise of the containerized application and potentially the host system (if combined with escape vulnerabilities).
  • Affected Component: libpod (image pulling), container runtime. Directly involves Podman's image management capabilities.
  • Risk Severity: High
  • Mitigation Strategies:
    • Use only trusted registries.
    • Implement image scanning.
    • Use image signing and verification (Podman's signature verification).
    • Regularly update base images.
    • Use minimal base images.

Threat: Image Layer Caching Poisoning (Code Injection)

• Threat: Image Layer Caching Poisoning (Code Injection)

  • Description: An attacker gains access to Podman's build cache and injects malicious code. Subsequent podman build commands unknowingly incorporate the attacker's code. This is a direct attack on Podman's build process.
  • Impact: Compromise of the containerized application and potentially the host.
  • Affected Component: Podman's build process (podman build), build cache storage. Directly involves Podman's build functionality.
  • Risk Severity: High
  • Mitigation Strategies:
    • Use a secure build environment.
    • Regularly clear the build cache.
    • Use isolated build systems.
    • Implement strong access controls on build servers and cache storage.
    • Use content-addressable storage for image layers.

Threat: Container Network Exposure (Unauthorized Access)

• Threat: Container Network Exposure (Unauthorized Access)

  • Description: A container's network is misconfigured using Podman's networking features, exposing services. An attacker accesses these exposed services. The vulnerability lies in how Podman's network configuration is used (or misused).
  • Impact: Unauthorized access to the application and its data.
  • Affected Component: libpod (network management), CNI plugins, container network configuration (podman run options, network creation). Directly involves Podman's network management capabilities.
  • Risk Severity: High
  • Mitigation Strategies:
    • Use Podman's network modes appropriately.
    • Explicitly expose only necessary ports (-p or --publish).
    • Avoid host mode unless strictly necessary.
    • Use container network policies (Calico, Cilium).
    • Implement host firewalls.
    • Use dedicated network namespaces for pods.

Threat: Vulnerabilities in Podman Daemon or conmon (Privilege Escalation)

• Threat: Vulnerabilities in Podman Daemon or conmon (Privilege Escalation)

  • Description: A vulnerability is discovered in the podman daemon (if used in daemon mode) or the conmon process (always used). An attacker exploits this vulnerability directly in Podman's code to gain control.
  • Impact: Potential for complete host compromise.
  • Affected Component: podman daemon (if used), conmon, libpod. Directly involves vulnerabilities within Podman itself.
  • Risk Severity: Critical
  • Mitigation Strategies:
    • Keep Podman and dependencies updated.
    • Review security advisories and apply patches.
    • Run Podman with least privileges (prefer rootless).
    • Monitor Podman's logs.

Threat: Improper Socket Permissions (Unauthorized Control)

• Threat: Improper Socket Permissions (Unauthorized Control)
  • Description: The Podman socket is exposed with overly permissive permissions. An unauthorized user on the host gains access to the socket and can issue commands directly to Podman, controlling containers.
  • Impact: Unauthorized control over containers, potential for data breaches, denial of service, or further exploitation.
  • Affected Component: Podman socket (/run/podman/podman.sock or user-specific socket), system permissions. Directly involves the Podman API endpoint.
  • Risk Severity: High
  • Mitigation Strategies:
    • Ensure the Podman socket has appropriate permissions.
    • Use SSH tunneling for remote access.
    • Avoid exposing the socket to untrusted networks.

Threat: Data Leakage via Shared Volumes (Data Exposure)

• Threat: Data Leakage via Shared Volumes (Data Exposure)
  • Description: Sensitive data is stored in a volume that is shared between multiple containers using Podman's volume management. A compromised container gains access to this data due to Podman's handling of the shared volume.
  • Impact: Data breach, unauthorized access to sensitive information.
  • Affected Component: Podman volumes (podman volume), container configuration. Directly involves Podman's volume management features.
  • Risk Severity: High
  • Mitigation Strategies:
    • Use separate volumes for different containers.
    • Use read-only mounts (:ro).
    • Encrypt sensitive data in volumes.
    • Implement access controls on the host.
    • Avoid mounting host directories directly.