CVE-2024-21887 Google Chronicle · YARA-L

Detect Ivanti Connect Secure Authenticated Command Injection (CVE-2024-21887) in Google Chronicle

CVE-2024-21887 is a critical authenticated command injection vulnerability (CVSS 9.1) in Ivanti Connect Secure and Policy Secure web components. When chained with the authentication bypass CVE-2023-46805, unauthenticated remote attackers can execute arbitrary commands on the appliance as root. Nation-state threat actors (UNC5221) exploited this as a zero-day to deploy LIGHTWIRE, WIREFIRE, and FRAMESTING web shells and conduct credential harvesting and lateral movement. CISA added this to the KEV catalog in January 2024.

MITRE ATT&CK

Tactic
Initial Access Execution Persistence Credential Access Lateral Movement

YARA-L Detection Query

Google Chronicle (YARA-L)
yaral 
rule ivanti_cve_2024_21887_command_injection {
  meta:
    author = "df00tech Detection Engineering"
    description = "Detects CVE-2024-21887 authenticated command injection against Ivanti Connect Secure and Policy Secure"
    severity = "CRITICAL"
    priority = "HIGH"
    reference = "https://nvd.nist.gov/vuln/detail/CVE-2024-21887"

  events:
    $req.metadata.event_type = "NETWORK_HTTP"
    $req.network.http.method = /POST|PUT|GET/
    (
      $req.network.http.request_url = /\/api\/v1\/totp\/user-backup-code/ or
      $req.network.http.request_url = /\/api\/v1\/.*archiving.*cloud-server-test/ or
      $req.network.http.request_url = /\/api\/v1\/.*maintenance/ or
      $req.network.http.request_url = /[;|&`\$(){}\[\]]/ or
      $req.network.http.request_url = /%(3[Bb]|7[Cc]|60)/ or
      $req.network.http.request_url = /(wget|curl|bash|python|chmod|mkfifo|base64)/
    )
    $req.network.http.response_code = /200|201|204/
    $req.principal.ip != ""

  condition:
    $req
}
critical severity high confidence

Chronicle YARA-L rule detecting CVE-2024-21887 command injection attempts against Ivanti Connect Secure and Policy Secure appliances by matching known vulnerable API paths and injection payload patterns in HTTP requests.

Data Sources

Chronicle HTTP LogsNetwork TelemetryProxy Logs

Required Tables

NETWORK_HTTP

False Positives & Tuning

  • Authorized API calls from known Ivanti administrator IP ranges
  • Security scanning tools performing vulnerability assessments
  • Ivanti support access sessions touching maintenance API endpoints
  • Automated orchestration tools interacting with Ivanti APIs for legitimate operations

Other platforms for CVE-2024-21887

Microsoft Sentinel (KQL) Splunk (SPL) Elastic Security (Elastic) IBM QRadar (QRadar) Sumo Logic CSE (Sumo) CrowdStrike LogScale (LogScale) All platforms (combined) →

Testing Methodology

Validate this detection against 4 adversary techniques from Atomic Red Team. Each test below lists the behaviour to exercise and the telemetry you should expect to see. Executable commands and cleanup steps are available with Pro.

  1. Test 1CVE-2024-21887 Command Injection via TOTP Backup Code Endpoint

    Expected signal: HTTP POST to /api/v1/totp/user-backup-code/ with shell metacharacters in request body, followed by file creation event in /tmp/ visible in process audit logs

  2. Test 2CVE-2023-46805 + CVE-2024-21887 Full Chain — Unauthenticated RCE

    Expected signal: Sequence of: GET to /dana-na/auth/saml-sso.cgi with path traversal, 200 response with session cookie, then PUT to /api/v1/system/maintenance/archiving/cloud-server-test-connection with shell metacharacters in host field, followed by outbound HTTP callback from appliance

  3. Test 3Post-Exploitation Web Shell Deployment Simulation

    Expected signal: File creation event at /home/webserver/htdocs/dana-na/auth/ for a new .pl or .py file; subsequent GET request to that file path with query parameters (cmd=, exec=, c=); process spawning by the web server daemon executing perl or python

  4. Test 4Credential Harvesting Simulation via Ivanti Config API

    Expected signal: GET requests to Ivanti configuration API endpoints for user-roles and authentication server configuration; successful 200 responses containing credential or LDAP bind DN data

Last updated: 2026-06-20 Research depth: standard
References (5)

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Related Detections

Tactic Hubs

TA0001Initial AccessTA0002ExecutionTA0003PersistenceTA0006Credential AccessTA0008Lateral Movement

Related Techniques

T1190Exploit Public-Facing ApplicationT1059Command and Scripting InterpreterT1505.003Web ShellT1078Valid AccountsT1560Archive Collected Data

Same Tactic: Initial Access

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