# Encrypted data accepted without integrity authentication

A protected data format permits security-relevant changes that are not detected before use.

**Candidate CWE:** [CWE-353](https://cwe.mitre.org/data/definitions/353.html)

## Test hypothesis

Identify the encryption mode and where integrity is checked. Save a valid synthetic message, change a controlled field or authenticated context in the local fixture, and compare processing with an invalid-tag control. Trace whether downstream code consumes plaintext before verification.

## Evidence required

Show the accepted modified value and resulting forbidden state; document key, nonce, tag, associated-data and parser assumptions. Nonce reuse is a separate cryptographic defect that needs its own demonstration.

## Rule out false positives

Encryption without an explicit MAC in one function may still be protected by authenticated encryption or an outer signed envelope. A rejected corruption or parser error is not authenticated forgery.

## Playbook and command references

- [Source review: entry point to protected operation](https://bug-bounty-field-manual.kmahshooq.chatgpt.site/modules/source-dataflow.html) — Trace attacker control and authorization through handlers, services, queues, and sensitive operations; promote only reachable violations of a stated invariant.
- [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=Source%20review%3A%20entry%20point%20to%20protected%20operation)

## Referenced by these target playbooks

[OSS & self-hosted](https://bug-bounty-field-manual.kmahshooq.chatgpt.site/oss.html) · [Web & API](https://bug-bounty-field-manual.kmahshooq.chatgpt.site/web-api.html) · [Mobile](https://bug-bounty-field-manual.kmahshooq.chatgpt.site/mobile.html) · [Desktop & extensions](https://bug-bounty-field-manual.kmahshooq.chatgpt.site/desktop.html) · [Hardware & firmware](https://bug-bounty-field-manual.kmahshooq.chatgpt.site/hardware.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

- [OWASP cryptographic storage](https://cheatsheetseries.owasp.org/cheatsheets/Cryptographic_Storage_Cheat_Sheet.html)

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