attack-tree.md

Attack Tree Analysis for denoland/deno

Objective: To achieve Remote Code Execution (RCE) on the server running the Deno application, or to exfiltrate sensitive data accessible to the Deno process.

Attack Tree Visualization

                                      +-------------------------------------+
                                      |  Attacker's Goal: RCE or Data      |
                                      |  Exfiltration on Deno Application  |
                                      +-------------------------------------+
                                                  |
         +----------------------------------+----------------------------------+
         |                                  |
+---------------------+        +---------------------+
|  Exploit Deno      |        |  Exploit Deno      |
|  Permissions       |        |  Standard Library  |
|  Model             |        |  or Dependencies   |
+---------------------+        +---------------------+
         |                                  |
+--------+--------+           +--------+--------+
|        |        |           |        |        |
| Overly | Insecure|           | Vuln.  | Supply |
| Perm.  | Use of  |           | in 3rd | Chain  |
| Env    | --allow |           | Party  | Attack |
| Vars   | -all    |           | Deps   | on Deps|
+--------+--------+           +--------+--------+
         |        |                     |
         |        |                     |
         | +------+------+             |
         | |      |      |             |
         | | Net  | Run  |             |
         | |[CRIT]| [CRIT]|             |
         | +------+------+             |
         |        |        |             |
         |  Leak  |  RCE   |             |
         |  Keys  |  via   |             |
         |  via   |  Shell |             |
         |  Env   |  Cmds  |             |
         +--------+--------+             |
                  |                     |
                  |                     |
                  +---------------------+
                  | [HIGH RISK]         |
                  +---------------------+

Attack Tree Path: 1. Exploit Deno Permissions Model (High-Risk Path):

• Overly Permissive Environment Variables:

  • Description: Sensitive data (API keys, database credentials) are stored in environment variables accessible to the Deno process. An attacker gaining even limited code execution can read these.
  • Likelihood: Medium
  • Impact: Medium to High
  • Effort: Very Low
  • Skill Level: Novice
  • Detection Difficulty: Easy/Hard (depending on monitoring)
  • Mitigation:
    • Use a secrets manager.
    • Minimize exposed environment variables.
    • Sanitize the environment before launching Deno.

• Insecure Use of --allow-all:

  • Description: Granting all permissions, providing an attacker with unrestricted access.
  • Likelihood: Low (should be avoided in production)
  • Impact: Very High
  • Effort: Very Low
  • Skill Level: Novice
  • Detection Difficulty: Very Easy
  • Mitigation:
    • Never use --allow-all in production.
    • Use specific permission flags.
    • Enforce code reviews and automated checks.

• --allow-net [CRITICAL]:

  • Description: Allows the Deno process to make arbitrary network connections.
  • Likelihood: Medium (many applications need network access)
  • Impact: Medium to High (data exfiltration, C2 communication)
  • Effort: Low
  • Skill Level: Intermediate
  • Detection Difficulty: Medium
  • Mitigation:
    • Restrict network access to specific hosts and ports.
    • Implement network monitoring.

• --allow-run [CRITICAL]:

  • Description: Allows the Deno process to execute arbitrary subprocesses.
  • Likelihood: Low (should be avoided if possible)
  • Impact: Very High (direct path to RCE)
  • Effort: Low
  • Skill Level: Intermediate to Advanced
  • Detection Difficulty: Medium to Hard
  • Mitigation:
    • Avoid --allow-run if possible.
    • Whitelist specific commands and arguments.
    • Thoroughly sanitize input.

• Leak Keys via Env (High Risk):

  • Description: A specific consequence of overly permissive environment variables, focusing on the high impact of leaking sensitive keys.
  • Likelihood: Medium
  • Impact: High
  • Effort: Very Low
  • Skill Level: Novice
  • Detection Difficulty: Easy/Hard (depending on monitoring)
  • Mitigation: Same as "Overly Permissive Environment Variables".

• RCE via Shell Cmds (High Risk):

  • Description: A specific consequence of using --allow-run, focusing on achieving RCE through shell command execution.
  • Likelihood: Low (if --allow-run is used)
  • Impact: Very High
  • Effort: Low
  • Skill Level: Intermediate to Advanced
  • Mitigation: Same as "--allow-run".

Attack Tree Path: 2. Exploit Deno Standard Library or Dependencies (High-Risk Path):

• Vulnerability in 3rd Party Dependencies:

  • Description: A security flaw in a third-party module imported into the Deno application.
  • Likelihood: Medium
  • Impact: Medium to High
  • Effort: Low to Medium
  • Skill Level: Intermediate to Advanced
  • Detection Difficulty: Medium
  • Mitigation:
    • Use dependency management tools.
    • Perform vulnerability scanning.
    • Regularly update dependencies.
    • Audit dependencies before adding them.

• Supply Chain Attack on Dependencies:

  • Description: An attacker compromises a dependency's repository or distribution, injecting malicious code.
  • Likelihood: Low
  • Impact: Very High
  • Effort: High to Very High
  • Skill Level: Advanced to Expert
  • Detection Difficulty: Hard
  • Mitigation:
    • Use lock files (deno.lock).
    • Utilize integrity checking.
    • Consider vendoring dependencies.
    • Use a private module registry.