Detection rules › Kusto
PulseConnectSecure - CVE-2021-22893 Possible Pulse Connect Secure RCE Vulnerability Attack
'This query identifies exploitation attempts using Pulse Connect Secure(PCS) vulnerability (CVE-2021-22893) to the VPN server'
MITRE ATT&CK coverage
| Tactic | Techniques |
|---|---|
| Initial Access | T1190 Exploit Public-Facing Application |
Rule body kusto
id: d0c82b7f-40b2-4180-a4d6-7aa0541b7599
name: PulseConnectSecure - CVE-2021-22893 Possible Pulse Connect Secure RCE Vulnerability Attack
description: |
'This query identifies exploitation attempts using Pulse Connect Secure(PCS) vulnerability (CVE-2021-22893) to the VPN server'
severity: High
requiredDataConnectors:
- connectorId: PulseConnectSecure
dataTypes:
- Syslog
queryFrequency: 1h
queryPeriod: 1h
triggerOperator: gt
triggerThreshold: 0
tactics:
- InitialAccess
relevantTechniques:
- T1190
query: |
let threshold = 3;
PulseConnectSecure
| where Messages contains "Unauthenticated request url /dana-na/"
| summarize StartTime = min(TimeGenerated), EndTime = max(TimeGenerated), count() by Source_IP
| where count_ > threshold
entityMappings:
- entityType: IP
fieldMappings:
- identifier: Address
columnName: Source_IP
version: 1.0.2
kind: Scheduled
metadata:
source:
kind: Community
author:
name: Sittikorn S
support:
tier: Community
categories:
domains: [ "Security - Threat Intelligence" ]
Stages and Predicates
Parameters
let threshold = 3;
Stage 1: source
PulseConnectSecure
Stage 2: where
| where Messages contains "Unauthenticated request url /dana-na/"
Stage 3: summarize
| summarize StartTime = min(TimeGenerated), EndTime = max(TimeGenerated), count() by Source_IP
Stage 4: where
| where count_ > threshold
Indicators
Each row is a field, operator, and value that the rule matches. The corpus column counts how many other rules in the catalog look for the same combination: high numbers point to widely-used, community-vetted indicators. Blank or 1 shows that the indicator is specific to this rule.
Output fields
Fields the rule emits when it matches. Chronicle authors list these in the outcome block; they appear on the detection and $risk_score drives alerting. Sentinel / Defender XDR rules build them up through project / summarize / extend stages. Sentinel maps these into alert fields via entityMappings and customDetails; Defender XDR custom detections surface them as alert fields directly.
| Field | Source |
|---|---|
EndTime | summarize |
Source_IP | summarize |
StartTime | summarize |