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CWE-212

保管または転送前の機密情報の不適切な除去

Improper Removal of Sensitive Information Before Storage or Transfer
脆弱性 作成中
JA

製品が機密情報を含むリソースを保存、転送、または共有しているが、そのリソースが権限のない行為者に利用される前に、その情報を適切に削除していない。

機密データを含む可能性のあるリソースには、文書、パケット、メッセージ、データベースなどがある。このようなデータは、リソースを共有する個々のユーザーや少数のユーザーにとっては有用かもしれませんが、信頼されたグループ以外でリソースを共有する前に削除する必要があるかもしれません。削除のプロセスは、クレンジングまたはスクラビングと呼ばれることもある。

例えば、ドキュメントを編集するための製品は、レビュアーのコメントやドキュメントが保存されているローカルのパス名などの機密データを削除しないかもしれません。あるいは、プロキシがインターネットサイトへの発信リクエストを行う前に、ヘッダーから内部IPアドレスを削除しないかもしれない。

EN

The product stores, transfers, or shares a resource that contains sensitive information, but it does not properly remove that information before the product makes the resource available to unauthorized actors.

Resources that may contain sensitive data include documents, packets, messages, databases, etc. While this data may be useful to an individual user or small set of users who share the resource, it may need to be removed before the resource can be shared outside of the trusted group. The process of removal is sometimes called cleansing or scrubbing.

For example, a product for editing documents might not remove sensitive data such as reviewer comments or the local pathname where the document is stored. Or, a proxy might not remove an internal IP address from headers before making an outgoing request to an Internet site.

Scope: Confidentiality / Impact: Read Files or Directories; Read Application Data
Clearly specify which information should be regarded as private or sensitive, and require that the product offers functionality that allows the user to cleanse the sensitive information from the resource before it is published or exported to other parties.
Compartmentalize the system to have "safe" areas where trust boundaries can be unambiguously drawn. Do not allow sensitive data to go outside of the trust boundary and always be careful when interfacing with a compartment outside of the safe area.

Ensure that appropriate compartmentalization is built into the system design, and the compartmentalization allows for and reinforces privilege separation functionality. Architects and designers should rely on the principle of least privilege to decide the appropriate time to use privileges and the time to drop privileges.
Some tools can automatically analyze
documents to redact, strip, or "sanitize" private
information, although some human review might be
necessary. Tools may vary in terms of which document
formats can be processed.

When calling an external program to automatically
generate or convert documents, invoke the program with
any available options that avoid generating sensitive
metadata. Some formats have well-defined fields that
could contain private data, such as Exchangeable image
file format (Exif), which can contain potentially
sensitive metadata such as geolocation, date, and time
[REF-1515] [REF-1516].
Use naming conventions and strong types to make it easier to spot when sensitive data is being used. When creating structures, objects, or other complex entities, separate the sensitive and non-sensitive data as much as possible.
Avoid errors related to improper resource shutdown or release (CWE-404), which may leave the sensitive data within the resource if it is in an incomplete state.
MITRE公式ページ — CWE-212