Controls/EDCA-TLS-031.json

{
  "id": "EDCA-TLS-031",
  "title": "Edge anti-spam agents are enabled",
  "description": "The Edge Transport server MUST have content filtering, recipient filtering, sender filtering, and connection filtering agents enabled. The Connection Filtering agent is enabled or disabled independently via Enable-TransportAgent / Disable-TransportAgent, not via a *-ConnectionFilterConfig cmdlet. Disabled anti-spam agents allow spam, phishing, and malicious mail to pass to internal mail servers without inspection.",
  "verify": true,
  "subject": "Server",
  "category": "Transport Security",
  "severity": "High",
  "severityWeight": 8,
  "frameworks": [
    "Best Practice",
    "DISA",
    "CISA"
  ],
  "references": [
    {
      "name": "Microsoft — Antispam protection in Exchange Server",
      "url": "https://learn.microsoft.com/exchange/antispam-and-antimalware/antispam-protection/antispam-protection"
    },
    {
      "name": "DISA STIG EX19-ED-000102: The Exchange content filter must be enabled (V-259626)",
      "url": "https://www.stigviewer.com/stigs/microsoft_exchange_2019_edge_server/2024-12-06/finding/V-259626"
    },
    {
      "name": "DISA STIG EX19-ED-000104: The Exchange Recipient Filter must be enabled (V-259627)",
      "url": "https://www.stigviewer.com/stigs/microsoft_exchange_2019_edge_server/2024-12-06/finding/V-259627"
    },
    {
      "name": "DISA STIG EX19-ED-000106: The Exchange Sender Filter must be enabled (V-259628)",
      "url": "https://www.stigviewer.com/stigs/microsoft_exchange_2019_edge_server/2024-12-06/finding/V-259628"
    }
  ],
  "remediation": {
    "automatable": false,
    "description": "Enable the relevant agent(s). For content, recipient, and sender filtering use Set-ContentFilterConfig -Enabled $true, Set-RecipientFilterConfig -Enabled $true, or Set-SenderFilterConfig -Enabled $true. For connection filtering, enable the Connection Filtering transport agent with Enable-TransportAgent 'Connection Filtering Agent' then restart the transport service.",
    "scriptTemplate": "Get-ContentFilterConfig | Select-Object Enabled\nGet-RecipientFilterConfig | Select-Object Enabled\nGet-SenderFilterConfig | Select-Object Enabled\nGet-TransportAgent -Identity 'Connection Filtering Agent' | Select-Object Identity,Enabled\n# To enable connection filtering:\n# Enable-TransportAgent 'Connection Filtering Agent'\n# Restart-Service MSExchangeTransport"
  },
  "considerations": "Enabling or tuning anti-spam agents may temporarily affect mail flow if the thresholds are misconfigured. Test in a staging environment when possible.",
  "roles": [
    "Edge"
  ]
}