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Anonymous connection

Description​

Due to an improper configuration of the server (e.g., an FTP service with username: anonymous and password: guest or an SMTP open relay), it is possible to make anonymous connections to it and access otherwise protected resources.

Impact​

Read and/or modify files within the service.

Recommendation​

Configure the services to avoid services enumeration or to connect to these anonymously.

Threat​

Anonymous attacker from adjacent network.

Expected Remediation Time​

⌚ 30 minutes.

Score​

Default score using CVSS 3.1. It may change depending on the context of the vulnerability.

Base​

  • Attack vector: A
  • Attack complexity: L
  • Privileges required: N
  • User interaction: N
  • Scope: U
  • Confidentiality: L
  • Integrity: L
  • Availability: N

Temporal​

  • Exploit code madurity: X
  • Remediation level: O
  • Report confidence: X

Result​

  • Vector string: CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:L/I:L/A:N/E:X/RL:O/RC:X
  • Score:
    • Base: 5.4
    • Temporal: 5.2
  • Severity:
    • Base: Medium
    • Temporal: Medium

Code Examples​

Compliant code​

Correctly configure services to deny anonymous authentication

{
  "$schema": "http://json.schemastore.org/launchsettings.json",
  "iisSettings": {
    "windowsAuthentication": false,
    "anonymousAuthentication": false,
  }
}

Non compliant code​

A service is configured to allow anonymous authentication

{
  "$schema": "http://json.schemastore.org/launchsettings.json",
  "iisSettings": {
    "windowsAuthentication": false,
    "anonymousAuthentication": true,
  }
}

Requirements​

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