iOS

Safely handling Share Extension input

Protecting data across devices, extensions, notifications and account changes.

iOS data and lifecycle1 min readEditorial methods

Shared content comes from another application. Treat filenames, type metadata and lengths as untrusted.

Evaluation approach

Define supported formats and bound processing of large or malformed input. Limit access to files passed into the main app.

Application example

A notes application should verify session validity when importing a shared PDF. Account changes during sharing need their own failure path.

Limits and considerations

Successful parsing does not establish business authorization.

Account changes during sharing

The account selected when an extension opens may differ at completion. Bind the operation to its verified starting context or require renewed approval. Do not attach a document to another user's space or leave unnecessary shared-directory copies after failure.

Checks and decisions

  • Validate formats
  • Limit size
  • Test session changes

Sources

The primary references above provide the technical basis. Example workflows and evaluation suggestions are this publication’s explanations, not independent test results for a particular product.