CWE-1021

レンダリングUIレイヤーまたはフレームの不適切な制限

Improper Restriction of Rendered UI Layers or Frames

脆弱性作成中

日本語説明

ウェブアプリケーションは、別のアプリケーションやドメインに属するフレームオブジェクトやUIレイヤーを制限しないか、間違って制限してしまうため、ユーザーがどのインターフェースとやりとりしているのか混乱する可能性があります。

ウェブアプリケーションは、フレーム、iframe、オブジェクト、embed、アプレットエレメント内でレンダリングすることが許可されているかどうかを制限することが期待されています。制限がないと、ユーザは意図しないのにアプリケーションとやりとりするように騙される可能性があります。

原文 (English)

The web application does not restrict or incorrectly restricts frame objects or UI layers that belong to another application or domain, which can lead to user confusion about which interface the user is interacting with.

A web application is expected to place restrictions on whether it is allowed to be rendered within frames, iframes, objects, embed or applet elements. Without the restrictions, users can be tricked into interacting with the application when they were not intending to.

関連する脆弱性

想定される影響

Scope: Access Control / Impact: Gain Privileges or Assume Identity; Bypass Protection Mechanism; Read Application Data; Modify Application Data

対策・緩和策

The use of X-Frame-Options allows developers of web content to restrict the usage of their application within the form of overlays, frames, or iFrames. The developer can indicate from which domains can frame the content.

The concept of X-Frame-Options is well documented, but implementation of this protection mechanism is in development to cover gaps. There is a need for allowing frames from multiple domains.

A developer can use a "frame-breaker" script in each page that should not be framed. This is very helpful for legacy browsers that do not support X-Frame-Options security feature previously mentioned.

It is also important to note that this tactic has been circumvented or bypassed. Improper usage of frames can persist in the web application through nested frames. The "frame-breaking" script does not intuitively account for multiple nested frames that can be presented to the user.

This defense-in-depth technique can be used to prevent the improper usage of frames in web applications. It prioritizes the valid sources of data to be loaded into the application through the usage of declarative policies. Based on which implementation of Content Security Policy is in use, the developer should use the "frame-ancestors" directive or the "frame-src" directive to mitigate this weakness. Both directives allow for the placement of restrictions when it comes to allowing embedded content.

外部リンク

MITRE公式ページ — CWE-1021