Skip to content

Latest commit

 

History

History
127 lines (96 loc) · 107 KB

sec-design-deep-analysis.md

File metadata and controls

127 lines (96 loc) · 107 KB

Okay, let's perform a deep security analysis of netch, based on the provided security design review.

1. Objective, Scope, and Methodology

  • Objective: To conduct a thorough security analysis of the netch network utility, focusing on identifying potential vulnerabilities in its design, implementation, and deployment. This includes analyzing the core components (CLI, Core Logic, Network Stack interactions), data flows, and build/deployment processes. The goal is to provide actionable recommendations to improve the security posture of netch.
  • Scope: The analysis will cover the following aspects of netch:
    • Command-line interface (CLI) argument parsing and input validation.
    • Core logic responsible for implementing network functions (e.g., ping, TCP connections, DNS lookups).
    • Interaction with the operating system's network stack.
    • Dependency management and the potential for supply chain attacks.
    • Build and deployment processes.
    • Data flow and potential exposure of sensitive information.
  • Methodology:
    1. Architecture and Component Inference: Based on the C4 diagrams and descriptions, we'll infer the detailed architecture, components, and data flow within netch. This will involve reasoning about how the different parts of the system interact.
    2. Threat Modeling: We'll apply threat modeling principles to identify potential threats and vulnerabilities, considering the business priorities, existing security controls, and accepted risks. We'll use the STRIDE model (Spoofing, Tampering, Repudiation, Information Disclosure, Denial of Service, Elevation of Privilege) as a framework.
    3. Security Control Analysis: We'll evaluate the effectiveness of existing security controls and identify gaps.
    4. Mitigation Strategy Recommendation: For each identified threat, we'll propose specific, actionable mitigation strategies tailored to netch's design and implementation.

2. Security Implications of Key Components

Let's break down the security implications of each key component, inferred from the design review:

  • 2.1 Command Line Interface (CLI):

    • Function: Parses command-line arguments, validates user input, and passes data to the Core Logic.
    • Threats:
      • Command Injection: If user-provided input (e.g., hostnames, IP addresses, ports) is directly used to construct shell commands or system calls without proper sanitization, an attacker could inject malicious commands. This is a high-severity threat.
      • Buffer Overflow: If the CLI doesn't properly handle excessively long input strings, it could lead to a buffer overflow, potentially allowing arbitrary code execution. This is a high-severity threat.
      • Denial of Service (DoS): Malformed input could cause the CLI to crash or consume excessive resources. This is a medium-severity threat.
      • Information Disclosure: Incorrect error handling or verbose output could reveal internal details about the system or network configuration. This is a low-to-medium severity threat.
    • Data Flow: User input (strings, numbers) -> CLI -> Core Logic.
    • Existing Controls: Input validation (mentioned, but details are needed).
    • Inferred Architecture: Likely uses a command-line argument parsing library (e.g., cobra, flag in Go). The specific validation logic needs to be examined in the code.

  • 2.2 Core Logic:

    • Function: Implements the core network functionality (ping, TCP connections, DNS lookups) by interacting with the OS network stack.
    • Threats:
      • Logic Errors: Incorrect implementation of network protocols could lead to incorrect results, unexpected behavior, or vulnerabilities. For example, a flawed ping implementation might misinterpret ICMP responses. This is a medium-severity threat.
      • Resource Exhaustion: Poorly managed network connections or timeouts could lead to resource exhaustion, causing a denial-of-service condition. This is a medium-severity threat.
      • Information Disclosure: If netch exposes internal state or debug information, it could aid attackers. This is a low-to-medium severity threat.
      • Dependency Vulnerabilities: Vulnerabilities in third-party libraries used by the Core Logic could be exploited. This is a medium-to-high severity threat, depending on the vulnerability.
    • Data Flow: Validated input from CLI -> Core Logic -> OS Network Stack -> Remote Server/DNS Server -> OS Network Stack -> Core Logic -> CLI -> User.
    • Existing Controls: Dependency management (Go modules), potential static analysis.
    • Inferred Architecture: Likely uses Go's standard library packages like net, net/http, crypto/tls for network operations.

  • 2.3 Network Stack (Operating System):

    • Function: Provides the low-level network access for netch.
    • Threats: netch itself has limited control over the security of the OS network stack. However, vulnerabilities in the OS network stack could be triggered by netch's actions. This is generally outside the direct control of netch, but netch should be designed to minimize the risk of triggering such vulnerabilities.
    • Data Flow: Interacts with Core Logic to send and receive network packets.
    • Existing Controls: Relies on the security of the underlying operating system.
    • Inferred Architecture: netch uses system calls to interact with the OS network stack.

  • 2.4 Build Process:

    • Function: Compiles the source code into executable binaries.
    • Threats:
      • Supply Chain Attacks: Compromised build tools, dependencies, or CI/CD pipeline could inject malicious code into the netch binaries. This is a high-severity threat.
      • Tampering: Unauthorized modification of build artifacts before distribution. This is a high-severity threat.
    • Data Flow: Source code -> Build tools -> Binaries -> Distribution.
    • Existing Controls: Automated build (CI/CD), dependency management (Go modules), version control.
    • Inferred Architecture: Uses GitHub Actions for CI/CD, Go build tools for compilation.

  • 2.5 Deployment (Manual Download and Execution):

    • Function: Distribute compiled binaries.
    • Threats:
      • Man-in-the-Middle (MitM) Attacks: If binaries are downloaded over an insecure connection (e.g., HTTP), an attacker could intercept and replace them with malicious versions. This is a high-severity threat.
      • Tampering: Unauthorized modification of binaries on the distribution platform (GitHub Releases). This is a high-severity threat.
    • Data Flow: GitHub Releases -> User's Machine.
    • Existing Controls: Relies on GitHub's security, potential code signing (recommended).
    • Inferred Architecture: Uses GitHub Releases as the distribution platform.

3. Threat Modeling (STRIDE)

| Threat Category | Specific Threat | Component(s) Affected | Severity | Mitigation Strategies (See Section 4)

4. Mitigation Strategies

Here are specific, actionable mitigation strategies tailored to the identified threats, referencing the relevant component and threat category:

  • 4.1 Input Validation and Sanitization (CLI, Core Logic - Command Injection, Buffer Overflow, DoS):

    • 4.1.1 Strict Input Validation: Implement rigorous validation for all user-supplied input. For IP addresses, use Go's net.ParseIP to validate IPv4 and IPv6 addresses. For hostnames, use a combination of regular expressions and DNS lookups (with timeouts) to ensure they are valid and resolvable. For port numbers, ensure they are integers within the range 1-65535. Reject any input that doesn't conform to the expected format. Do not rely solely on regular expressions for hostname validation, as they can be bypassed.
    • 4.1.2 Parameterization/Prepared Statements: If netch constructs any shell commands or system calls (even indirectly), never directly embed user input into the command string. Instead, use parameterized commands or the equivalent in Go (e.g., using exec.Command with separate arguments). This prevents attackers from injecting arbitrary commands. This is crucial if netch ever interacts with the shell.
    • 4.1.3 Length Limits: Enforce strict length limits on all input fields (hostnames, IP addresses, etc.) to prevent buffer overflows. Use Go's string manipulation functions safely, being mindful of potential overflows. Consider using bufio.Scanner with a maximum token size for reading input.
    • 4.1.4 Input Encoding/Decoding: If any input is used in contexts where special characters have meaning (e.g., URLs, HTML), properly encode or decode the input to prevent injection attacks. Use Go's url.QueryEscape and html.EscapeString where appropriate.
    • 4.1.5 Error Handling: Provide user-friendly error messages for invalid input without revealing sensitive system information. Avoid stack traces or internal error codes in user-facing output.

  • 4.2 Core Logic Protections (Core Logic - Logic Errors, Resource Exhaustion, Information Disclosure):

    • 4.2.1 Safe Network Libraries: Use Go's built-in net package and related packages (net/http, crypto/tls) for all network operations. These libraries are well-vetted and regularly updated. Avoid using third-party networking libraries unless absolutely necessary and thoroughly vetted.
    • 4.2.2 Timeouts and Connection Management: Implement appropriate timeouts for all network operations (DNS lookups, TCP connections, ping requests). Use Go's context package extensively to manage timeouts and cancellations. Properly close connections and release resources after use to prevent resource exhaustion. Use connection pooling where appropriate to improve efficiency and reduce the risk of resource leaks.
    • 4.2.3 Error Handling and Logging: Implement robust error handling for all network operations. Log errors (with appropriate severity levels) to a file or system log, but never log sensitive information (e.g., full network packets, internal IP addresses of other systems). Use a structured logging library (e.g., zap, logrus) for consistent and manageable logs.
    • 4.2.4 Protocol Validation: If netch implements any custom parsing of network protocols (e.g., ICMP, DNS responses), ensure that the parsing logic is robust and handles malformed packets gracefully. Fuzz testing (see below) is particularly important here.
    • 4.2.5 Avoid Unnecessary Information: Do not include unnecessary information in responses or logs. For example, don't echo back the full user-provided input in error messages.

  • 4.3 Dependency Management (Core Logic, Build Process - Supply Chain Attacks):

    • 4.3.1 Dependency Scanning: Integrate a dependency vulnerability scanner (e.g., snyk, dependabot, govulncheck) into the CI/CD pipeline. This will automatically scan go.mod and go.sum for known vulnerabilities in dependencies and generate alerts or pull requests for updates. This is a critical control.
    • 4.3.2 Vendor Dependencies: Consider vendoring dependencies (using go mod vendor) to ensure that the build process uses a known, controlled set of dependencies. This mitigates the risk of a compromised dependency being pulled from the public repository during the build.
    • 4.3.3 Review Dependencies: Regularly review the dependencies listed in go.mod and go.sum to ensure they are still necessary and actively maintained. Remove any unused or outdated dependencies.

  • 4.4 Build Process Security (Build Process - Supply Chain Attacks, Tampering):

    • 4.4.1 Secure CI/CD Pipeline: Ensure the CI/CD pipeline (GitHub Actions) is configured securely. Use strong authentication, restrict access to the pipeline configuration, and regularly review audit logs.
    • 4.4.2 Build Artifact Signing: Digitally sign the released binaries using a code signing certificate. This allows users to verify the authenticity and integrity of the downloaded binaries. Go provides tools for this (e.g., cosign). This is a very important control.
    • 4.4.3 SBOM Generation: Generate a Software Bill of Materials (SBOM) during the build process. This provides a list of all components and dependencies used in netch, making it easier to track and manage vulnerabilities. Tools like syft can be used for this.
    • 4.4.4 Reproducible Builds: Aim for reproducible builds. This means that building the same source code multiple times should produce bit-for-bit identical binaries. This helps to ensure that the build process hasn't been tampered with.

  • 4.5 Deployment Security (Deployment - MitM Attacks, Tampering):

    • 4.5.1 HTTPS Distribution: Ensure that binaries are downloaded over HTTPS (which GitHub Releases already uses). This protects against MitM attacks during download.
    • 4.5.2 Checksum Verification: Provide checksums (e.g., SHA-256) for the released binaries. Users should verify the checksum of the downloaded binary against the published checksum to ensure it hasn't been tampered with.
    • 4.5.3 Code Signing Verification: Instruct users on how to verify the digital signature of the downloaded binaries.

  • 4.6 Testing (All Components):

    • 4.6.1 Comprehensive Static Analysis: Use a robust static analysis tool specifically designed for Go (e.g., golangci-lint, staticcheck, gosec). Configure the tool to check for a wide range of security vulnerabilities and code quality issues. Integrate this into the CI/CD pipeline.
    • 4.6.2 Fuzz Testing: Implement fuzz testing to provide a wide range of invalid, unexpected, or random inputs to netch. This can help identify crashes, buffer overflows, and other vulnerabilities that might be missed by traditional testing. Use Go's built-in fuzzing capabilities (go test -fuzz). Focus fuzzing on input parsing, network protocol handling, and any areas that handle user-provided data.
    • 4.6.3 Unit and Integration Tests: Write comprehensive unit and integration tests to ensure that all components of netch function correctly and handle edge cases gracefully.

  • 4.7 Operating System Interaction (Network Stack):

    • 4.7.1 Least Privilege: Ensure netch runs with the minimum necessary privileges. Avoid requiring root/administrator privileges unless absolutely necessary for specific functionality. If elevated privileges are needed for certain features, clearly document this and provide a way to run those features separately.
    • 4.7.2 Secure System Calls: When making system calls, use the most secure and recommended methods provided by the Go standard library. Avoid using deprecated or unsafe functions.

This detailed analysis provides a strong foundation for improving the security of netch. By implementing these mitigation strategies, the development team can significantly reduce the risk of vulnerabilities and protect users from potential attacks. Remember to prioritize the "high-severity" threats first. Regularly review and update these security measures as the project evolves.