Sigma Rule Library

Exploitation Indicators Of CVE-2023-20198

Detecting exploitation indicators of CVE-2023-20198 a privilege escalation vulnerability in Cisco IOS XE Software Web UI.

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Detection logic

keyword_event

- "%WEBUI-6-INSTALL_OPERATION_INFO:"
- "%SYS-5-CONFIG_P:"
- "%SEC_LOGIN-5-WEBLOGIN_SUCCESS:"

keyword_user

- cisco_tac_admin
- cisco_support
- cisco_sys_manager

Condition

keyword_event and keyword_user

Raw YAML

title: Exploitation Indicators Of CVE-2023-20198
id: 2ece8816-b7a0-4d9b-b0e8-ae7ad18bc02b
status: test
description: Detecting exploitation indicators of CVE-2023-20198 a privilege escalation vulnerability in Cisco IOS XE Software Web UI.
references:
    - https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-iosxe-webui-privesc-j22SaA4z
    - https://www.thestack.technology/security-experts-call-for-incident-response-exercises-after-mass-cisco-device-exploitation/
author: Lars B. P. Frydenskov (Trifork Security)
date: 2023-10-20
tags:
    - attack.privilege-escalation
    - attack.initial-access
    - detection.emerging-threats
logsource:
    product: cisco
    service: syslog
    definition: 'Requirements: Cisco IOS XE system logs needs to be configured and ingested'
detection:
    keyword_event:
        - '%WEBUI-6-INSTALL_OPERATION_INFO:'
        - '%SYS-5-CONFIG_P:'
        - '%SEC_LOGIN-5-WEBLOGIN_SUCCESS:'
    keyword_user:
        - 'cisco_tac_admin'
        - 'cisco_support'
        - 'cisco_sys_manager'
    condition: keyword_event and keyword_user
falsepositives:
    - Rare false positives might occur if there are valid users named "cisco_tac_admin" or "cisco_support", which are not created by default or CISCO representatives
level: high

False positives

  • Rare false positives might occur if there are valid users named "cisco_tac_admin" or "cisco_support", which are not created by default or CISCO representatives

References