# Extension input crosses an iOS shared-container boundary

The main application trusts content written through a lower-trust extension/input path as if it were an authorized app action.

**Candidate CWE:** [CWE-863](https://cwe.mitre.org/data/definitions/863.html)

## Test hypothesis

Map group membership and intended sharing, import one synthetic document through the real extension, and compare the main app’s treatment of expected and invalid metadata.

## Evidence required

Entitlements, signed participants, share-sheet or other real entry, controlled file/message and the resulting protected operation.

## Rule out false positives

App Group membership is not itself a leak. Signing the attacker app with the victim team or granting matching entitlements changes the attacker model.

## Playbook and command references

- [iOS signing capabilities, links and protected data](https://bug-bounty-field-manual.kmahshooq.chatgpt.site/modules/ios-boundaries.html) — Connect entitlements and application groups to actual callers, URL transitions and protected key use.
- [Uploads, downloads, paths, archives, and XML](https://bug-bounty-field-manual.kmahshooq.chatgpt.site/modules/file-boundaries.html) — Follow a file through acceptance, storage, processing, publication, and retrieval while preserving ownership and path boundaries.

[Find the associated command snippets](https://bug-bounty-field-manual.kmahshooq.chatgpt.site/commands.html?q=iOS%20signing%20capabilities%2C%20links%20and%20protected%20data)

## Referenced by these target playbooks

[Mobile](https://bug-bounty-field-manual.kmahshooq.chatgpt.site/mobile.html)

## Report checklist

- [ ] Capture the affected version, configuration, identities, and object ownership.
- [ ] Preserve a valid baseline and a negative control.
- [ ] Reproduce the forbidden data access, action, or state change on controlled fixtures.
- [ ] Explain the intended security rule and why the observed behavior violates it.
- [ ] State prerequisites, uncertainty, cleanup, and the smallest demonstrated impact.

## Conditional ATT&CK mapping

No direct ATT&CK mapping selected. Record the weakness and demonstrated impact without forcing an adversary-behavior classification. See the [mapping guide](https://bug-bounty-field-manual.kmahshooq.chatgpt.site/attack.html).

## Primary references

- [Apple app protection and groups](https://support.apple.com/guide/security/app-protection-and-app-groups-sec1a976c067/web)

[Back to the complete vulnerability catalog](https://bug-bounty-field-manual.kmahshooq.chatgpt.site/vulnerabilities.html)