stack/docs/scratchpads/274-command-injection.md

Issue #274: Sanitize agent spawn command payloads (command injection risk)

Objective

Add input validation and sanitization to agent spawn command payloads to prevent command injection vulnerabilities in git operations.

Security Impact

Severity: P0 (Critical) - Blocks production deployment Attack Vector: Federated instances can inject malicious commands via branch names Risk: Command injection in git operations allowing arbitrary code execution

Vulnerability Details

Attack Flow

1. Attacker sends federation command with malicious branch name
2. Payload passes through command service without validation
3. Branch name used directly in git worktree add command
4. Malicious git syntax executed on orchestrator

Vulnerable Code

File: apps/orchestrator/src/git/worktree-manager.service.ts:82

await git.raw(["worktree", "add", worktreePath, "-b", branchName, baseBranch]);

Input Source: Federation command payload → no validation → git command

Attack Example

{
  "commandType": "agent.spawn",
  "payload": {
    "context": {
      "branch": "feature/--config user.core.sshCommand=malicious"
    }
  }
}

Approach

1. Add Input Validation DTOs

• Strict regex for branch names (alphanumeric + hyphens + underscores + slashes)
• Repository URL validation (https/ssh only)
• Reject dangerous characters (;, $, `, --, etc.)

2. Create Sanitization Utility

• Whitelist-based approach
• Validate before any git operation
• Clear error messages on rejection

3. Apply at Multiple Layers

• DTO validation (first line of defense)
• Service-level sanitization (defense in depth)
• Git operation wrapper (last resort)

Progress

• Create validation utility
• Update SpawnAgentDto with strict validation
• Update SpawnAgentCommandPayload type
• Add sanitization in WorktreeManagerService
• Add tests for validation
• Add tests for sanitization
• Security vulnerability FIXED
• Create PR
• Merge to develop
• Close issue #274

Implementation Status

IN PROGRESS - Adding input validation and sanitization