[preview] 验证并隔离导入游戏对同源编辑器的访问

[jamiesun]

Context Boundary

• Repo/module: talkincode/GameKit, ZIP import and Pygame preview
• Version/commit: main, 9eb811e7bc3db3193b57609425723c478e438d32
• Runtime: imported project code runs in a same-origin /play/<session>/ iframe
• OS/browser: not recorded; browser proof of concept has not been run in this review
• Dependencies/config: pygbag 0.9.3 runtime; no sandbox flag on the iframe

Expectation vs. Reality

Expected: A project imported from a ZIP is treated as untrusted code and cannot inspect or modify the GameKit editor page or its project storage when Run is pressed.

Actual: The preview iframe is same-origin and has no sandbox attribute. The pygbag template exposes platform.window.parent through its Python-to-JavaScript bridge for its own debug messages. Source inspection therefore indicates that project code may be able to reach the parent GameKit page and same-origin browser APIs. This is a security-boundary finding, not a confirmed production incident; a benign browser proof of concept is still needed.

Reproduction Path

1. In a throwaway project with no personal data, add a benign probe that attempts to set platform.window.parent.document.title to GameKit preview probe.
2. Run the project and check whether the parent page title changes.
3. Record the browser/runtime result; do not test against real project data or send data to an external host.

Minimal reproduction:

import platform
platform.window.parent.document.title = "GameKit preview probe"

Blast Radius

• Affected users/paths: users who run projects imported from untrusted ZIPs.
• Frequency: only when potentially untrusted project code is executed.
• Severity rationale: if the bridge is reachable from project code, the same-origin editor and locally stored projects may be exposed; recommend P1 pending browser validation and an explicit trust-model decision.
• Workaround: only run source that the user trusts until isolation is verified.

Evidence

• Preview iframe has no sandbox: PreviewPane.tsx
• Runtime exposes platform.window and posts to platform.window.parent: player.tmpl, debug bridge
• ZIP import accepts project files including Python source: projectFromArchive