CVE-2026-32746: Advanced Linux Networking Mitigation Tool

🚨 TECHNICAL DISCLAIMER

CVE-2026-32746 is a hypothetical vulnerability used for educational demonstrations. This tool addresses the "Perfect Storm" scenario: A memory-unsafe Telnet daemon (telnetd) combined with a race condition in privilege elevation, leading to a remote root instruction pointer (IP) hijack.

🛠 Features (v3.1 - Production Grade)

The tool has evolved into a modular security framework with the following capabilities:

• 🔄 Atomic Rollback System:
  • Pre-flight State Capture: Automatically serializes current system state (services & firewall rules) to JSON before any remediation.
  • One-Command Reversal: Use --rollback to restore the system to its original state if a conflict occurs.
• 🛡️ Multi-Firewall Strategy Pattern:
  • Heterogeneous Support: Auto-detects and supports UFW, firewalld, nftables, and iptables.
• 🧱 Defense-in-Depth Remediations:
  • Service Masking: Uses systemctl mask to prevent inadvertent restarts by dependencies.
  • Port Auditing: Real-time listening port verification via ss and netstat.

📐 System Architecture

Modular Component Design

The tool follows a Strategy pattern to handle heterogeneous Linux environments.

classDiagram
    class MitigationTool {
        +args
        +run() int
    }
    class StateManager {
        +save_state()
        +rollback()
    }
    class FirewallManager {
        +backend: FirewallBackend
        +block_port(port)
    }
    class FirewallBackend {
        <<interface>>
        +is_available() bool
        +is_active() bool
        +block_port(port)
    }
    
    MitigationTool *-- StateManager
    MitigationTool *-- FirewallManager
    FirewallManager o-- FirewallBackend
    FirewallBackend <|-- UFWBackend
    FirewallBackend <|-- FirewalldBackend
    FirewallBackend <|-- IptablesBackend
    FirewallBackend <|-- NftablesBackend

Remediation Workflow

The following sequence describes the atomic "capture-before-fix" logic:

sequenceDiagram
    participant User
    participant Tool as MitigationTool
    participant SM as StateManager
    participant FM as FirewallManager
    participant SV as ServiceManager

    User->>Tool: --apply-fixes
    Tool->>SM: save_state(POTENTIAL_SERVICES, firewall, port)
    activate SM
    SM->>SM: Capture systemd states
    SM->>SM: Save to .cve_2026_32746_state.json
    SM-->>Tool: State Captured
    deactivate SM

    Tool->>SV: remediate(active_services)
    SV->>SV: stop / disable / mask
    
    Tool->>FM: block_port(23)
    FM->>FM: Apply Firewall Strategy (UFW/Firewalld/etc)
    
    Tool-->>User: Success (Exit 0)

📋 Prerequisites

• Python 3.10+
• Root privileges (sudo)
• Linux (Systemd support recommended)

🚀 Usage

1. Audit and Remediate

sudo ./telnet_mitigation_tool.py --apply-fixes

2. Rollback Changes

Instantly restore system state from the captured snapshot.

sudo ./telnet_mitigation_tool.py --rollback

3. Dry-Run Rollback

Preview exactly what changes the rollback will perform.

sudo ./telnet_mitigation_tool.py --rollback --dry-run

🏗 Project Structure

• telnet_mitigation_tool.py: Core modular execution engine.
• test_v3_logic.py: Unit test suite supporting modular firewall backends.
• CHANGELOG.md: Historical version notes.
• .cve_2026_32746_state.json: Local state storage (created during remediation).

⚖ License

This project is licensed under the MIT License - see the LICENSE file for details.