# (L2) Ensure meeting chat does not allow anonymous users

Meeting chat is open to everyone who is in the meeting. If anonymous users can use it, a person who has joined without signing in can post messages and…

Source: https://maester.dev/docs/tests/CIS.M365.8.5.5

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<div class="test-byline"><div class="test-byline-avatars"><a class="test-byline-avatar test-byline-avatar--author" href="/contributors/jeremyfinney-lgtm" title="jeremy finney · Original author"><img src="https://github.com/JeremyFinney-lgtm.png" alt="jeremy finney" width="28" height="28" loading="lazy" decoding="async" /></a></div><div class="test-byline-meta"><span class="test-byline-text">Contributed by <a href="/contributors/jeremyfinney-lgtm">jeremy finney</a></span><a class="test-byline-link" href="/contributors">All contributors →</a></div></div>

<p class="test-part">Part of <a href="/docs/tests/cis">CIS</a> · Teams · Meetings · <a href="/docs/tests">All checks</a></p>

```powershell title="Run this check"
Invoke-Maester -TestId CIS.M365.8.5.5
```

## Overview

Meeting chat is open to everyone who is in the meeting. If anonymous users can use it, a person who has joined without signing in can post messages and links to all participants, which is a route for phishing and social engineering during a meeting.

Limiting meeting chat to signed-in participants keeps the chat to people whose identity is known. Anonymous participants can still listen and watch the meeting.

#### Remediation action

1. Sign in to the [Microsoft Teams admin center](https://admin.teams.microsoft.com).
2. Go to **Meetings** > **Meeting policies**.
3. Open the **Global (Org-wide default)** policy.
4. Under **Meeting chat**, select **On for everyone but anonymous users** or **Off**.
5. Select **Save**.

##### PowerShell

1. Connect to Teams PowerShell using `Connect-MicrosoftTeams`.
2. Run the following command:

```powershell
Set-CsTeamsMeetingPolicy -Identity Global -MeetingChatEnabledType EnabledExceptAnonymous
```

#### Related links

* [Microsoft Teams admin center](https://admin.teams.microsoft.com)
* [Manage meeting policies in Microsoft Teams](https://learn.microsoft.com/microsoftteams/meeting-policies-in-teams)
* [Set-CsTeamsMeetingPolicy](https://learn.microsoft.com/powershell/module/teams/set-csteamsmeetingpolicy)
* [CIS Microsoft 365 Foundations Benchmark v7.0.0 - 8.5.5](https://www.cisecurity.org/benchmark/microsoft_365)

## Details

<details>
<summary>Every attribute of this check</summary>

| Field | Value |
| --- | --- |
| Test ID | CIS.M365.8.5.5 |
| Severity | Medium |
| Suite | CIS |
| Product | Teams |
| Feature | Meetings |
| Area | External access and sharing |
| Resource type | Tenant |
| User impact | Low |
| Implementation cost | Low |
| MITRE ATT&CK | T1566 Phishing |
| Supports benchmark | CIS Microsoft 365 Foundations Benchmark (version 7.0.0), requirement 8.5.5 |
| Benchmark level | L2 |
| Benchmark profiles | E3 Level 2 |
| Supports controls | cis-m365:8.5.5, nist-800-53-r5:AC-3 |
| PowerShell test | [Test-MtCisTeamsMeetingChatAnonymous](https://github.com/maester365/maester/blob/main/tests/cis/Test.CIS.M365.8.5.5.ps1) |
| Services | Teams |

</details>

## Source

- Test: [`tests/cis/Test.CIS.M365.8.5.5.ps1`](https://github.com/maester365/maester/blob/main/tests/cis/Test.CIS.M365.8.5.5.ps1)
- Documentation: [`tests/cis/Test.CIS.M365.8.5.5.md`](https://github.com/maester365/maester/blob/main/tests/cis/Test.CIS.M365.8.5.5.md)