```json
[
  {
    "severity": "Critical",
    "issue": "Path Traversal",
    "exploit": "An attacker can provide a path parameter containing directory traversal sequences (e.g., `../../etc/passwd`). Because the `path` parameter is directly concatenated to the base directory without sanitization, the resulting file path resolves outside the intended `/srv/reports/` directory, allowing the attacker to read arbitrary files on the server.",
    "fix": "Validate and sanitize the `path` parameter to ensure it only contains safe characters (e.g., alphanumeric, hyphens, underscores, dots) and does not contain `..` or `/`. Additionally, use `os.path.realpath()` to resolve the full path and verify it starts with the intended base directory before serving the file."
  },
  {
    "severity": "High",
    "issue": "Timing Attack on Token Comparison",
    "exploit": "The token comparison `token != os.environ[\"ADMIN_TOKEN\"]` uses a standard string comparison operator, which short-circuits on the first mismatched character. An attacker can measure the response time to determine how many characters of the token are correct, allowing them to brute-force the token character by character.",
    "fix": "Use a constant-time comparison function, such as `hmac.compare_digest()`, to compare the provided token with the environment variable token. This ensures the comparison takes the same amount of time regardless of where the mismatch occurs."
  },
  {
    "severity": "Medium",
    "issue": "Information Disclosure via Error Handling",
    "exploit": "If the requested file does not exist or the path is invalid, `FileResponse` may raise an exception that leaks server-side information, such as the operating system type, directory structure, or Python stack traces, depending on the application's error handling configuration.",
    "fix": "Implement a try-except block around the `FileResponse` call to catch `FileNotFoundError` and other potential exceptions, returning a generic 404 or 500 response without exposing internal details."
  }
]
```