Hardware Firewall Supply chain attack accepted

THREAT150 · Accepted: The team has decided to live with this risk. · Defined in catalog.py:2579

Risk: Medium impact × Low likelihood = 4 medium
After mitigations: Medium impact × Low likelihood = 4 medium (unchanged)

Hardware firewall shipment intercepted and malware has been implanted. An adversary that has compromised the hardware firewall will be able to eavesdrop/inject network traffic to and from the SecureDrop Area.

Threat actors: Nation State / Law Enforcement

Mitigations

Mitigation	Status
Source interface only available as a Tor onion service MITIG54	implemented
Journalist interface only available as a Tor onion service MITIG55	implemented
Admin interface traffic goes over Tor MITIG96	implemented
apt performs GPG signature verification as long as it's not explicitly disabled MITIG167	implemented
Restrictive iptables rules on servers MITIG182	implemented

Possible further mitigations

Buy retail hardware where possible MITIG118 proposed
Inspect physical hardware for implants (not really possible in many cases) MITIG119 proposed
Valid-Until for apt packages MITIG194 proposed
Use authenticated version of NTP to harden against e.g. DNS attacks - tlsdate? research needed here MITIG97 proposed

Residual risk

Malicious APT package uploaded by person in control of the key. Potential replay of old apt packages and denial of service through NTP (Tor will fail to complete circuit if the clock is not accurate)

Where it applies

Applies to 1 component in 5 scenarios.

Dedicated Hardware Firewall SecureDrop Area

Source submission · Dedicated Hardware Firewall

digraph tm {
    graph [
        fontname = Arial;
        fontsize = 14;
    ]
    node [
        fontname = Arial;
        fontsize = 14;
    ]
    edge [
        fontname = Arial;
        fontsize = 12;
    ]
    nodesep = 1;

    subgraph cluster_boundary_Application_Server {
        graph [
            fontsize = 10;
            fontcolor = black;
            style = dashed;
            color = firebrick2;
            label = <<i>Application Server</i>>;
        ]

        component_Encrypted_submission_store_Application_Server [
            shape = circle;
            color = black;
            fontcolor = black;
            label = "Encrypted\nsubmission store";
            URL = "component_Encrypted_submission_store.html";
            tooltip = "Encrypted submission store";
            margin = 0.02;
        ]

        component_Metadata_DB_Application_Server [
            shape = circle;
            color = black;
            fontcolor = black;
            label = "Metadata DB";
            URL = "component_Metadata_DB.html";
            tooltip = "Metadata DB";
            margin = 0.02;
        ]

        component_SecureDrop_Application_Application_Server [
            shape = circle;
            color = black;
            fontcolor = black;
            label = "SecureDrop\nApplication";
            URL = "component_SecureDrop_Application.html";
            tooltip = "SecureDrop Application";
            margin = 0.02;
        ]

        component_Source_Interface_Application_Server [
            shape = circle;
            color = black;
            fontcolor = black;
            label = "Source Interface";
            URL = "component_Source_Interface.html";
            tooltip = "Source Interface";
            margin = 0.02;
        ]

    }

    subgraph cluster_boundary_SecureDrop_Area {
        graph [
            fontsize = 10;
            fontcolor = black;
            style = dashed;
            color = firebrick2;
            label = <<i>SecureDrop Area</i>>;
        ]

        component_Dedicated_Hardware_Firewall_SecureDrop_Area [
            shape = circle;
            color = black;
            fontcolor = black;
            label = "Dedicated\nHardware\nFirewall";
            URL = "component_Dedicated_Hardware_Firewall.html";
            tooltip = "Dedicated Hardware Firewall";
            margin = 0.02;

            style = "filled";

            fillcolor = "#c0392b";

            fontcolor = "white";

            class = "highlighted";
        ]

    }

    subgraph cluster_boundary_Source_Area {
        graph [
            fontsize = 10;
            fontcolor = black;
            style = dashed;
            color = firebrick2;
            label = <<i>Source Area</i>>;
        ]

        actor_Source_Source_Area [
            shape = square;
            color = black;
            fontcolor = black;
            label = "Source";
            URL = "component_Source.html";
            tooltip = "Source";
            margin = 0.02;
        ]

    }

    actor_Source_Source_Area -> component_Dedicated_Hardware_Firewall_SecureDrop_Area [        color = black;        fontcolor = black;        dir = forward;        label = "1. Submit over Tor";    ]
    component_Dedicated_Hardware_Firewall_SecureDrop_Area -> component_Source_Interface_Application_Server [        color = black;        fontcolor = black;        dir = forward;        label = "2. Reach Source\nInterface";    ]
    component_Source_Interface_Application_Server -> component_SecureDrop_Application_Application_Server [        color = black;        fontcolor = black;        dir = forward;        label = "3. Hand to app";    ]
    component_SecureDrop_Application_Application_Server -> component_Encrypted_submission_store_Application_Server [        color = black;        fontcolor = black;        dir = forward;        label = "4. Encrypt & store";    ]
    component_SecureDrop_Application_Application_Server -> component_Metadata_DB_Application_Server [        color = black;        fontcolor = black;        dir = forward;        label = "5. Record metadata";    ]
}

Journalist triage · Dedicated Hardware Firewall

digraph tm {
    graph [
        fontname = Arial;
        fontsize = 14;
    ]
    node [
        fontname = Arial;
        fontsize = 14;
    ]
    edge [
        fontname = Arial;
        fontsize = 12;
    ]
    nodesep = 1;

    subgraph cluster_boundary_Application_Server {
        graph [
            fontsize = 10;
            fontcolor = black;
            style = dashed;
            color = firebrick2;
            label = <<i>Application Server</i>>;
        ]

        component_Encrypted_submission_store_Application_Server [
            shape = circle;
            color = black;
            fontcolor = black;
            label = "Encrypted\nsubmission store";
            URL = "component_Encrypted_submission_store.html";
            tooltip = "Encrypted submission store";
            margin = 0.02;
        ]

        component_Journalist_Interface_Application_Server [
            shape = circle;
            color = black;
            fontcolor = black;
            label = "Journalist\nInterface";
            URL = "component_Journalist_Interface.html";
            tooltip = "Journalist Interface";
            margin = 0.02;
        ]

        component_Metadata_DB_Application_Server [
            shape = circle;
            color = black;
            fontcolor = black;
            label = "Metadata DB";
            URL = "component_Metadata_DB.html";
            tooltip = "Metadata DB";
            margin = 0.02;
        ]

    }

    subgraph cluster_boundary_SecureDrop_Area {
        graph [
            fontsize = 10;
            fontcolor = black;
            style = dashed;
            color = firebrick2;
            label = <<i>SecureDrop Area</i>>;
        ]

        component_Dedicated_Hardware_Firewall_SecureDrop_Area [
            shape = circle;
            color = black;
            fontcolor = black;
            label = "Dedicated\nHardware\nFirewall";
            URL = "component_Dedicated_Hardware_Firewall.html";
            tooltip = "Dedicated Hardware Firewall";
            margin = 0.02;

            style = "filled";

            fillcolor = "#c0392b";

            fontcolor = "white";

            class = "highlighted";
        ]

    }

    actor_Journalist_ [
        shape = square;
        color = black;
        fontcolor = black;
        label = "Journalist";
        URL = "component_Journalist.html";
        tooltip = "Journalist";
        margin = 0.02;
    ]

    actor_Journalist_ -> component_Dedicated_Hardware_Firewall_SecureDrop_Area [        color = black;        fontcolor = black;        dir = forward;        label = "1. Authenticate over\nTor";    ]
    component_Dedicated_Hardware_Firewall_SecureDrop_Area -> component_Journalist_Interface_Application_Server [        color = black;        fontcolor = black;        dir = forward;        label = "2. Reach Journalist\nInterface";    ]
    component_Journalist_Interface_Application_Server -> component_Metadata_DB_Application_Server [        color = black;        fontcolor = black;        dir = forward;        label = "3. List sources";    ]
    component_Encrypted_submission_store_Application_Server -> actor_Journalist_ [        color = black;        fontcolor = black;        dir = forward;        label = "4. Download\nencrypted";    ]
}

Admin access · Dedicated Hardware Firewall

digraph tm {
    graph [
        fontname = Arial;
        fontsize = 14;
    ]
    node [
        fontname = Arial;
        fontsize = 14;
    ]
    edge [
        fontname = Arial;
        fontsize = 12;
    ]
    nodesep = 1;

    subgraph cluster_boundary_Application_Server {
        graph [
            fontsize = 10;
            fontcolor = black;
            style = dashed;
            color = firebrick2;
            label = <<i>Application Server</i>>;
        ]

        component_App_Server_SSH_Application_Server [
            shape = circle;
            color = black;
            fontcolor = black;
            label = "App Server SSH";
            URL = "component_App_Server_SSH.html";
            tooltip = "App Server SSH";
            margin = 0.02;
        ]

    }

    subgraph cluster_boundary_Monitoring_Server {
        graph [
            fontsize = 10;
            fontcolor = black;
            style = dashed;
            color = firebrick2;
            label = <<i>Monitoring Server</i>>;
        ]

        component_Monitor_Server_SSH_Monitoring_Server [
            shape = circle;
            color = black;
            fontcolor = black;
            label = "Monitor Server\nSSH";
            URL = "component_Monitor_Server_SSH.html";
            tooltip = "Monitor Server SSH";
            margin = 0.02;
        ]

    }

    subgraph cluster_boundary_SecureDrop_Area {
        graph [
            fontsize = 10;
            fontcolor = black;
            style = dashed;
            color = firebrick2;
            label = <<i>SecureDrop Area</i>>;
        ]

        component_Dedicated_Hardware_Firewall_SecureDrop_Area [
            shape = circle;
            color = black;
            fontcolor = black;
            label = "Dedicated\nHardware\nFirewall";
            URL = "component_Dedicated_Hardware_Firewall.html";
            tooltip = "Dedicated Hardware Firewall";
            margin = 0.02;

            style = "filled";

            fillcolor = "#c0392b";

            fontcolor = "white";

            class = "highlighted";
        ]

    }

    actor_Administrator_ [
        shape = square;
        color = black;
        fontcolor = black;
        label = "Administrator";
        URL = "component_Administrator.html";
        tooltip = "Administrator";
        margin = 0.02;
    ]

    actor_Administrator_ -> component_Dedicated_Hardware_Firewall_SecureDrop_Area [        color = black;        fontcolor = black;        dir = forward;        label = "1. SSH over Tor";    ]
    component_Dedicated_Hardware_Firewall_SecureDrop_Area -> component_App_Server_SSH_Application_Server [        color = black;        fontcolor = black;        dir = forward;        label = "2. Admin App Server";    ]
    component_Dedicated_Hardware_Firewall_SecureDrop_Area -> component_Monitor_Server_SSH_Monitoring_Server [        color = black;        fontcolor = black;        dir = forward;        label = "3. Admin Monitor\nServer";    ]
}

Updates, time & DNS · Dedicated Hardware Firewall

digraph tm {
    graph [
        fontname = Arial;
        fontsize = 14;
    ]
    node [
        fontname = Arial;
        fontsize = 14;
    ]
    edge [
        fontname = Arial;
        fontsize = 12;
    ]
    nodesep = 1;

    subgraph cluster_boundary_Application_Server {
        graph [
            fontsize = 10;
            fontcolor = black;
            style = dashed;
            color = firebrick2;
            label = <<i>Application Server</i>>;
        ]

        component_App_Server_APT_NTP_DNS_Application_Server [
            shape = circle;
            color = black;
            fontcolor = black;
            label = "App Server\nAPT/NTP/DNS";
            URL = "component_App_Server_APT_NTP_DNS.html";
            tooltip = "App Server APT/NTP/DNS";
            margin = 0.02;
        ]

    }

    subgraph cluster_boundary_External_Services {
        graph [
            fontsize = 10;
            fontcolor = black;
            style = dashed;
            color = firebrick2;
            label = <<i>External Services</i>>;
        ]

        component_DNS_resolver_External_Services [
            shape = circle;
            color = black;
            fontcolor = black;
            label = "DNS resolver";
            URL = "component_DNS_resolver.html";
            tooltip = "DNS resolver";
            margin = 0.02;
        ]

        component_FPF_apt_repository_External_Services [
            shape = circle;
            color = black;
            fontcolor = black;
            label = "FPF apt\nrepository";
            URL = "component_FPF_apt_repository.html";
            tooltip = "FPF apt repository";
            margin = 0.02;
        ]

        component_NTP_server_External_Services [
            shape = circle;
            color = black;
            fontcolor = black;
            label = "NTP server";
            URL = "component_NTP_server.html";
            tooltip = "NTP server";
            margin = 0.02;
        ]

        component_Ubuntu_apt_repository_External_Services [
            shape = circle;
            color = black;
            fontcolor = black;
            label = "Ubuntu apt\nrepository";
            URL = "component_Ubuntu_apt_repository.html";
            tooltip = "Ubuntu apt repository";
            margin = 0.02;
        ]

    }

    subgraph cluster_boundary_Monitoring_Server {
        graph [
            fontsize = 10;
            fontcolor = black;
            style = dashed;
            color = firebrick2;
            label = <<i>Monitoring Server</i>>;
        ]

        component_Monitor_Server_APT_NTP_DNS_Monitoring_Server [
            shape = circle;
            color = black;
            fontcolor = black;
            label = "Monitor Server\nAPT/NTP/DNS";
            URL = "component_Monitor_Server_APT_NTP_DNS.html";
            tooltip = "Monitor Server APT/NTP/DNS";
            margin = 0.02;
        ]

    }

    subgraph cluster_boundary_SecureDrop_Area {
        graph [
            fontsize = 10;
            fontcolor = black;
            style = dashed;
            color = firebrick2;
            label = <<i>SecureDrop Area</i>>;
        ]

        component_Dedicated_Hardware_Firewall_SecureDrop_Area [
            shape = circle;
            color = black;
            fontcolor = black;
            label = "Dedicated\nHardware\nFirewall";
            URL = "component_Dedicated_Hardware_Firewall.html";
            tooltip = "Dedicated Hardware Firewall";
            margin = 0.02;

            style = "filled";

            fillcolor = "#c0392b";

            fontcolor = "white";

            class = "highlighted";
        ]

    }

    component_App_Server_APT_NTP_DNS_Application_Server -> component_Monitor_Server_APT_NTP_DNS_Monitoring_Server [        color = black;        fontcolor = black;        dir = forward;        label = "1. Proxy via monitor";    ]
    component_Monitor_Server_APT_NTP_DNS_Monitoring_Server -> component_Dedicated_Hardware_Firewall_SecureDrop_Area [        color = black;        fontcolor = black;        dir = forward;        label = "2. Egress via\nfirewall";    ]
    component_Dedicated_Hardware_Firewall_SecureDrop_Area -> component_Ubuntu_apt_repository_External_Services [        color = black;        fontcolor = black;        dir = forward;        label = "3. Ubuntu apt";    ]
    component_Dedicated_Hardware_Firewall_SecureDrop_Area -> component_FPF_apt_repository_External_Services [        color = black;        fontcolor = black;        dir = forward;        label = "4. FPF apt";    ]
    component_Dedicated_Hardware_Firewall_SecureDrop_Area -> component_NTP_server_External_Services [        color = black;        fontcolor = black;        dir = forward;        label = "5. NTP";    ]
    component_Dedicated_Hardware_Firewall_SecureDrop_Area -> component_DNS_resolver_External_Services [        color = black;        fontcolor = black;        dir = forward;        label = "6. DNS";    ]
}

Source discovery and OPSEC · Dedicated Hardware Firewall

digraph tm {
    graph [
        fontname = Arial;
        fontsize = 14;
    ]
    node [
        fontname = Arial;
        fontsize = 14;
    ]
    edge [
        fontname = Arial;
        fontsize = 12;
    ]
    nodesep = 1;

    subgraph cluster_boundary_External_Services {
        graph [
            fontsize = 10;
            fontcolor = black;
            style = dashed;
            color = firebrick2;
            label = <<i>External Services</i>>;
        ]

        component_Landing_page_External_Services [
            shape = circle;
            color = black;
            fontcolor = black;
            label = "Landing page";
            URL = "component_Landing_page.html";
            tooltip = "Landing page";
            margin = 0.02;
        ]

        component_SecureDrop_org_directory_External_Services [
            shape = circle;
            color = black;
            fontcolor = black;
            label = "SecureDrop.org\ndirectory";
            URL = "component_SecureDrop_org_directory.html";
            tooltip = "SecureDrop.org directory";
            margin = 0.02;
        ]

    }

    subgraph cluster_boundary_SecureDrop_Area {
        graph [
            fontsize = 10;
            fontcolor = black;
            style = dashed;
            color = firebrick2;
            label = <<i>SecureDrop Area</i>>;
        ]

        component_Dedicated_Hardware_Firewall_SecureDrop_Area [
            shape = circle;
            color = black;
            fontcolor = black;
            label = "Dedicated\nHardware\nFirewall";
            URL = "component_Dedicated_Hardware_Firewall.html";
            tooltip = "Dedicated Hardware Firewall";
            margin = 0.02;

            style = "filled";

            fillcolor = "#c0392b";

            fontcolor = "white";

            class = "highlighted";
        ]

    }

    subgraph cluster_boundary_Source_Area {
        graph [
            fontsize = 10;
            fontcolor = black;
            style = dashed;
            color = firebrick2;
            label = <<i>Source Area</i>>;
        ]

        actor_Source_Source_Area [
            shape = square;
            color = black;
            fontcolor = black;
            label = "Source";
            URL = "component_Source.html";
            tooltip = "Source";
            margin = 0.02;
        ]

        component_Source_Tor_Browser_Source_Area [
            shape = circle;
            color = black;
            fontcolor = black;
            label = "Source Tor\nBrowser";
            URL = "component_Source_Tor_Browser.html";
            tooltip = "Source Tor Browser";
            margin = 0.02;
        ]

        component_Source_environment_Source_Area [
            shape = circle;
            color = black;
            fontcolor = black;
            label = "Source\nenvironment";
            URL = "component_Source_environment.html";
            tooltip = "Source environment";
            margin = 0.02;
        ]

    }

    actor_Source_Source_Area -> component_Source_environment_Source_Area [        color = black;        fontcolor = black;        dir = forward;        label = "1. Research / browse";    ]
    component_Source_environment_Source_Area -> component_SecureDrop_org_directory_External_Services [        color = black;        fontcolor = black;        dir = forward;        label = "2. Check directory";    ]
    component_Source_environment_Source_Area -> component_Landing_page_External_Services [        color = black;        fontcolor = black;        dir = forward;        label = "3. Visit landing\npage";    ]
    actor_Source_Source_Area -> component_Source_Tor_Browser_Source_Area [        color = black;        fontcolor = black;        dir = forward;        label = "4. Open Tor Browser";    ]
    component_Source_Tor_Browser_Source_Area -> component_Dedicated_Hardware_Firewall_SecureDrop_Area [        color = black;        fontcolor = black;        dir = forward;        label = "5. Connect to onion";    ]
}

Notes

Existing mitigations: Senstive data is exchanged over encrypted and authenticated channel (Tor) (MITIG54, MITIG55, MITIG96). APT packages are signed (MITIG167). DNS, NTP remain as the only un-authenticated protocols. ipables is used as a Host-based firewall on app and mon servers for defense-in-depth (MITIG182). Further mitigations: Admins encouraged to buy retail hardware where possible (MITIG118). Inform administrators to inspect/compare equipment as it is received (MITIG119). Use Valid-Until for apt packages (MITIG194). Use secure version of NTP (MITIG97). Automated test for mitigation: No.

How this threat is matched

Listed for these components. A boundary covers every component inside it.