ESXi Firewall Disabled
Last updated 2 days ago on 2026-07-17
About
This detection identifies when the ESXi firewall is disabled or set to permissive mode, which can expose the host to unauthorized access and network-based attacks. Such changes are often a precursor to lateral movement, data exfiltration, or the installation of malicious software by a threat actor.
- Platform
Splunk
- Tags
- Data Source: SplunkDomain: ApplicationRule Type: QueryOS: Any
- Severity
- medium
- Risk Score
- 47
- False Positives
- Limited false positives in most environments, however tune as needed.
- Source
- View on GitHub(external, opens in a new tab or window)
Definition
- Rule Language
- SPL
- Rule Type
- query
text code block:`esxi_syslog` Message="*network firewall set*" AND Message="*enabled f*" | rex field=_raw "Z (?<dest>[\w\.]+)\s" | stats min(_time) as firstTime max(_time) as lastTime count by dest Message | `security_content_ctime(firstTime)` | `security_content_ctime(lastTime)` | `esxi_firewall_disabled_filter`
View this rule on Splunk
This rule was sourced from the official Splunk public repository. View the original rule on GitHub(external, opens in a new tab or window).