Unknown vulnerabilities in Python or libraries used by SecureDrop accepted

THREAT38 · Accepted: The team has decided to live with this risk. · Defined in catalog.py:678

Risk: High impact × Low likelihood = 6 medium
After mitigations: High impact × Low likelihood = 6 medium (unchanged)

Unknown vulnerabilities in Python libraries use could lead to code execution or denial of serviceon the app server

Threat actors: Nation State / Law Enforcement

Mitigations

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

Possible further mitigations

Move SecureDrop to a compiled, memory-safe language like Rust to reduce likelihood of code injection/modification MITIG175 proposed

Residual risk

Risk is accepted.

Where it applies

Applies to 1 component in 2 scenarios.

Source Interface Application Server

Source submission · Source Interface

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;

            style = "filled";

            fillcolor = "#c0392b";

            fontcolor = "white";

            class = "highlighted";
        ]

    }

    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;
        ]

    }

    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";    ]
}

Supply chain and dependencies · Source Interface

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;
        ]

        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;

            style = "filled";

            fillcolor = "#c0392b";

            fontcolor = "white";

            class = "highlighted";
        ]

    }

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

        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_SecureDrop_release___package_build_External_Services [
            shape = circle;
            color = black;
            fontcolor = black;
            label = "SecureDrop\nrelease &\npackage build";
            URL = "component_SecureDrop_release___package_build.html";
            tooltip = "SecureDrop release & package build";
            margin = 0.02;
        ]

        component_SecureDrop_source_repository_External_Services [
            shape = circle;
            color = black;
            fontcolor = black;
            label = "SecureDrop\nsource\nrepository";
            URL = "component_SecureDrop_source_repository.html";
            tooltip = "SecureDrop source repository";
            margin = 0.02;
        ]

        component_Tor_software_External_Services [
            shape = circle;
            color = black;
            fontcolor = black;
            label = "Tor software";
            URL = "component_Tor_software.html";
            tooltip = "Tor software";
            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;
        ]

    }

    component_SecureDrop_source_repository_External_Services -> component_SecureDrop_release___package_build_External_Services [        color = black;        fontcolor = black;        dir = forward;        label = "1. Build from source";    ]
    component_SecureDrop_release___package_build_External_Services -> component_FPF_apt_repository_External_Services [        color = black;        fontcolor = black;        dir = forward;        label = "2. Publish packages";    ]
    component_FPF_apt_repository_External_Services -> component_App_Server_APT_NTP_DNS_Application_Server [        color = black;        fontcolor = black;        dir = forward;        label = "3. Install / update";    ]
    component_Ubuntu_apt_repository_External_Services -> component_App_Server_APT_NTP_DNS_Application_Server [        color = black;        fontcolor = black;        dir = forward;        label = "4. Ubuntu\ndependencies";    ]
    component_Tor_software_External_Services -> component_Source_Interface_Application_Server [        color = black;        fontcolor = black;        dir = forward;        label = "5. Tor dependency";    ]
}

Notes

In scope: No. Existing mitigations: 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). Further mitigations: Consider moving SecureDrop to a compiled, memory-safe language like Rust to reduce likelihood of code injection/modification (MITIG175). Automated test for mitigation: No.

How this threat is matched

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