Sigma Rule Library

Cleartext Protocol Usage

Ensure that all account usernames and authentication credentials are transmitted across networks using encrypted channels. Ensure that an encryption is used for all sensitive information in transit. Ensure that an encrypted channels is used for all administrative account access.

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Detection logic

selection

dst_port:
  - 8080
  - 21
  - 80
  - 23
  - 50000
  - 1521
  - 27017
  - 3306
  - 1433
  - 11211
  - 15672
  - 5900
  - 5901
  - 5902
  - 5903
  - 5904

selection_allow1

action:
  - forward
  - accept
  - 2

selection_allow2

blocked: "false"

Condition

selection and 1 of selection_allow*

Raw YAML

title: Cleartext Protocol Usage
id: d7fb8f0e-bd5f-45c2-b467-19571c490d7e
status: stable
description: |
    Ensure that all account usernames and authentication credentials are transmitted across networks using encrypted channels.
    Ensure that an encryption is used for all sensitive information in transit. Ensure that an encrypted channels is used for all administrative account access.
references:
    - https://www.cisecurity.org/controls/cis-controls-list/
    - https://www.pcisecuritystandards.org/documents/PCI_DSS_v3-2-1.pdf
    - https://nvlpubs.nist.gov/nistpubs/CSWP/NIST.CSWP.04162018.pdf
author: Alexandr Yampolskyi, SOC Prime, Tim Shelton
date: 2019-03-26
modified: 2022-10-10
tags:
    - attack.credential-access
    # - CSC4
    # - CSC4.5
    # - CSC14
    # - CSC14.4
    # - CSC16
    # - CSC16.5
    # - NIST CSF 1.1 PR.AT-2
    # - NIST CSF 1.1 PR.MA-2
    # - NIST CSF 1.1 PR.PT-3
    # - NIST CSF 1.1 PR.AC-1
    # - NIST CSF 1.1 PR.AC-4
    # - NIST CSF 1.1 PR.AC-5
    # - NIST CSF 1.1 PR.AC-6
    # - NIST CSF 1.1 PR.AC-7
    # - NIST CSF 1.1 PR.DS-1
    # - NIST CSF 1.1 PR.DS-2
    # - ISO 27002-2013 A.9.2.1
    # - ISO 27002-2013 A.9.2.2
    # - ISO 27002-2013 A.9.2.3
    # - ISO 27002-2013 A.9.2.4
    # - ISO 27002-2013 A.9.2.5
    # - ISO 27002-2013 A.9.2.6
    # - ISO 27002-2013 A.9.3.1
    # - ISO 27002-2013 A.9.4.1
    # - ISO 27002-2013 A.9.4.2
    # - ISO 27002-2013 A.9.4.3
    # - ISO 27002-2013 A.9.4.4
    # - ISO 27002-2013 A.8.3.1
    # - ISO 27002-2013 A.9.1.1
    # - ISO 27002-2013 A.10.1.1
    # - PCI DSS 3.2 2.1
    # - PCI DSS 3.2 8.1
    # - PCI DSS 3.2 8.2
    # - PCI DSS 3.2 8.3
    # - PCI DSS 3.2 8.7
    # - PCI DSS 3.2 8.8
    # - PCI DSS 3.2 1.3
    # - PCI DSS 3.2 1.4
    # - PCI DSS 3.2 4.3
    # - PCI DSS 3.2 7.1
    # - PCI DSS 3.2 7.2
    # - PCI DSS 3.2 7.3
logsource:
    category: firewall
detection:
    selection:
        dst_port:
            - 8080
            - 21
            - 80
            - 23
            - 50000
            - 1521
            - 27017
            - 3306
            - 1433
            - 11211
            - 15672
            - 5900
            - 5901
            - 5902
            - 5903
            - 5904
    selection_allow1:
        action:
            - forward
            - accept
            - 2
    selection_allow2:
        blocked: "false" # not all fws set action value, but are set to mark as blocked or allowed or not
    condition: selection and 1 of selection_allow*
falsepositives:
    - Unknown
level: low

False positives

  • Unknown

References