attack-surface.md

Attack Surface Analysis for netchx/netch

Attack Surface: Command Injection

Description: An attacker injects malicious commands into system commands executed by the application. This occurs when user-provided input is not properly sanitized before being used in shell commands.

• How netch Contributes: netch likely uses system commands like ping, traceroute, dig, or nmap to perform network checks. If the hostname, IP address, or other parameters passed to these commands are derived from user input without proper sanitization, command injection vulnerabilities can arise directly due to netch's reliance on system commands.
• Example: A user provides the input ; rm -rf / as the hostname to be checked. If the application directly uses this input in a ping command facilitated by netch without sanitization, it could result in the execution of `ping ''; rm -rf /``, potentially deleting all files on the server if the application has sufficient privileges.
• Impact: Critical. Successful command injection can lead to complete system compromise, data loss, service disruption, and unauthorized access.
• Risk Severity: Critical
• Mitigation Strategies:
  • Strict Input Validation: Implement rigorous input validation and sanitization for all user-provided inputs that are used in network checks (hostnames, IP addresses, ports, etc.) before passing them to netch functions. Use allow-lists and regular expressions to define valid input formats.
  • Parameterized Commands or Safe Libraries: Avoid directly constructing shell commands by concatenating strings within netch's execution context if possible, or in the application code interacting with netch. Utilize parameterized command execution methods or libraries that offer safe command execution and prevent injection. Ideally, netch itself should be designed to minimize direct shell command construction if feasible, or the application using it must handle sanitization before calling netch.
  • Principle of Least Privilege: Run the application component that uses netch with the minimum necessary privileges. Avoid running it as root or administrator. This limits the impact of command injection if it occurs within the netch context.

Attack Surface: DNS Rebinding Attacks

Description: An attacker manipulates DNS records to initially resolve to a safe IP address during initial checks, but then changes the DNS to point to a malicious or internal IP address for subsequent requests. This can bypass intended access controls.

• How netch Contributes: If the application relies on hostname resolution based on user input processed by netch without proper safeguards against DNS rebinding, it becomes vulnerable. The initial check performed by netch might pass, but later interactions could be redirected to a malicious target. netch's hostname resolution functionality, if not carefully managed, directly opens this attack vector.
• Example:
  1. A user requests a network check for attacker-controlled-domain.com through the application using netch.
  2. Initially, attacker-controlled-domain.com resolves to a safe, attacker-controlled server (e.g., 1.2.3.4). The netch check passes.
  3. The attacker then changes the DNS record for attacker-controlled-domain.com to point to an internal server IP address (e.g., 192.168.1.100).
  4. Subsequent operations by the application using the resolved IP for attacker-controlled-domain.com obtained via netch's resolution might now inadvertently target the internal server 192.168.1.100, potentially bypassing firewalls or access controls.
• Impact: High. Can lead to unauthorized access to internal resources, data exfiltration, and potential exploitation of internal systems.
• Risk Severity: High
• Mitigation Strategies:
  • Validate Resolved IP Addresses: After resolving a hostname using netch or its underlying mechanisms, validate that the resolved IP address is within an expected range or not a private/internal IP address if external access is expected. The application using netch needs to perform this validation after netch provides the resolved IP.
  • Use IP Addresses Directly When Possible: If the application's logic allows, prefer using IP addresses directly instead of hostnames to avoid DNS-related attacks. This reduces reliance on netch's hostname resolution in security-sensitive contexts.
  • Implement DNS Pinning or Caching with Short TTLs: Cache DNS resolutions for very short periods (short TTLs) and potentially implement DNS pinning to detect changes in DNS records after initial resolution. This needs to be implemented in the application layer around netch's usage.
  • Consider using a dedicated DNS resolver with rebinding protection: Some DNS resolver libraries offer built-in protection against DNS rebinding attacks. If netch allows customization of the DNS resolver, or if the application can control DNS resolution before calling netch, this is a valuable mitigation.

Attack Surface: Privilege Escalation (Indirectly via Command Injection)

Description: While not directly a vulnerability in netch itself, if the application component utilizing netch runs with elevated privileges, command injection vulnerabilities within the netch context can be exploited to gain higher privileges on the system.

• How netch Contributes: If the application is designed in a way that the netch functionality is executed with elevated privileges (e.g., root or administrator), any command injection vulnerability arising from netch's system command usage becomes a privilege escalation vulnerability. netch's design, if it encourages or necessitates privileged execution, indirectly contributes to this risk.
• Example: If a web application using netch runs a component as root to perform network checks using netch, and a command injection vulnerability is exploited through user input to netch, the attacker can execute arbitrary commands as root, gaining full control of the system.
• Impact: Critical. Full system compromise, complete control over the system, and potential for widespread damage.
• Risk Severity: Critical
• Mitigation Strategies:
  • Principle of Least Privilege (Crucial): Absolutely minimize the privileges of the application component that uses netch. Avoid running it with elevated privileges unless absolutely unavoidable and only after extremely careful security review. This is paramount when using netch due to the inherent risks of system command execution.
  • Robust Command Injection Prevention (Primary Defense): Prioritize and rigorously implement all command injection mitigation strategies mentioned in point 1. This is the most direct way to prevent privilege escalation via netch.
  • Security Audits and Penetration Testing: Conduct thorough security audits and penetration testing to identify and eliminate any potential command injection vulnerabilities, especially in privileged contexts where netch is used.