Known vulnerabilities in the Linux kernel or packages used by app/mon servers mitigated

THREAT41 · Mitigated: Controls in place bring the risk down to an acceptable level. · Defined in catalog.py:730

Risk: High impact × Low likelihood = 6 medium
After mitigations: High impact × Very Low likelihood = 3 low

Known vulnerabilities in the Linux kernel or any package used by app a mon servers may

Threat actors: Any

Mitigations

Mitigation	Status
Automatic updates on servers MITIG43	implemented
Use of grsecurity-hardened kernels on servers MITIG53	implemented
AppArmor on Tor MITIG1	implemented
AppArmor on Apache MITIG2	implemented
Use of OSSEC monitoring software MITIG5	implemented

Where it applies

Applies to 2 components in 1 scenario.

Application Server (host) Application Server
Monitoring Server (host) Monitoring Server

Physical and host layer · Application Server (host), Monitoring Server (host)

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_Application_Server__host__Application_Server [
            shape = circle;
            color = black;
            fontcolor = black;
            label = "Application\nServer (host)";
            URL = "component_Application_Server__host_.html";
            tooltip = "Application Server (host)";
            margin = 0.02;

            style = "filled";

            fillcolor = "#c0392b";

            fontcolor = "white";

            class = "highlighted";
        ]

        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;
        ]

    }

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

        component_Monitoring_Server__host__Monitoring_Server [
            shape = circle;
            color = black;
            fontcolor = black;
            label = "Monitoring\nServer (host)";
            URL = "component_Monitoring_Server__host_.html";
            tooltip = "Monitoring Server (host)";
            margin = 0.02;

            style = "filled";

            fillcolor = "#c0392b";

            fontcolor = "white";

            class = "highlighted";
        ]

        component_OSSEC_server_Monitoring_Server [
            shape = circle;
            color = black;
            fontcolor = black;
            label = "OSSEC server";
            URL = "component_OSSEC_server.html";
            tooltip = "OSSEC server";
            margin = 0.02;
        ]

    }

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

        component_SecureDrop_server_room_SecureDrop_Area [
            shape = circle;
            color = black;
            fontcolor = black;
            label = "SecureDrop\nserver room";
            URL = "component_SecureDrop_server_room.html";
            tooltip = "SecureDrop server room";
            margin = 0.02;
        ]

    }

    component_SecureDrop_Application_Application_Server -> component_Application_Server__host__Application_Server [        color = black;        fontcolor = black;        dir = forward;        label = "1. Services on app\nhost";    ]
    component_OSSEC_server_Monitoring_Server -> component_Monitoring_Server__host__Monitoring_Server [        color = black;        fontcolor = black;        dir = forward;        label = "2. Services on mon\nhost";    ]
    component_Application_Server__host__Application_Server -> component_SecureDrop_server_room_SecureDrop_Area [        color = black;        fontcolor = black;        dir = forward;        label = "3. Hosts in server\nroom";    ]
}

Notes

Existing mitigations: A cron job ensures that automatic nightly security updates are applied for OS packages (MITIG43). Grsecurity/PaX linux patches prevent the exploitation of certain memory-corruption attacks (MITIG53). AppArmor profiles further reduce process capabilities through Mandatory Access Control (MITIG1, MITIG2). OSSEC is used for intrusion detection/file integrity monitoring (MITIG5). Automated test for mitigation: No.

How this threat is matched

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