# Unauthorized authenticator enrollment, replacement, or removal

A lower-assurance or wrong-account context can add, replace, or remove an authentication factor contrary to its management policy.

**Candidate CWE:** [CWE-287](https://cwe.mitre.org/data/definitions/287.html)

## Test hypothesis

In a disposable account, capture the legitimate factor-change flow. Compare required recent proof with stale, omitted, or other-account proof; independently test completed and MFA-pending sessions. Confirm a newly added factor through a fresh login, or a removed factor through one further login attempt.

## Evidence required

Expected factor-management rule, actor authentication state, factor owner before/after, exact changed proof, and a fresh protected-account result. Keep a recovery route and remove the test factor.

## Rule out false positives

A renamed label, intentional recovery process with adequate proof, or optional notification missing without any unauthorized factor change is insufficient.

## Playbook and command references

- [MFA and passkeys: enrollment, proof, replacement, and recovery](https://bug-bounty-field-manual.kmahshooq.chatgpt.site/modules/authenticator-lifecycle.html) — Follow each authenticator from account binding to removal, and validate WebAuthn assertions without mistaking client UI or counter behavior for a security guarantee.
- [Authentication, recovery, federation, and session lifecycle](https://bug-bounty-field-manual.kmahshooq.chatgpt.site/modules/identity-session.html) — Test registration, recovery, identity changes, invitations, SSO enforcement, and deprovisioning as one account state machine.

[Find the associated command snippets](https://bug-bounty-field-manual.kmahshooq.chatgpt.site/commands.html?q=MFA%20and%20passkeys%3A%20enrollment%2C%20proof%2C%20replacement%2C%20and%20recovery)

## Referenced by these target playbooks

[Web & API](https://bug-bounty-field-manual.kmahshooq.chatgpt.site/web-api.html) · [OSS & self-hosted](https://bug-bounty-field-manual.kmahshooq.chatgpt.site/oss.html) · [Mobile](https://bug-bounty-field-manual.kmahshooq.chatgpt.site/mobile.html) · [Desktop & extensions](https://bug-bounty-field-manual.kmahshooq.chatgpt.site/desktop.html) · [Cloud & containers](https://bug-bounty-field-manual.kmahshooq.chatgpt.site/cloud.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 Multifactor Authentication](https://cheatsheetseries.owasp.org/cheatsheets/Multifactor_Authentication_Cheat_Sheet.html)
- [NIST SP 800-63B-4](https://pages.nist.gov/800-63-4/sp800-63b.html)

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