Detect Ivanti Endpoint Manager (EPM) Authentication Bypass (CVE-2026-1603) in CrowdStrike LogScale
CVE-2026-1603 is an authentication bypass vulnerability (CWE-288) in Ivanti Endpoint Manager (EPM). This KEV-listed vulnerability allows unauthenticated attackers to bypass authentication mechanisms and gain unauthorized access to the EPM management interface. Successful exploitation may lead to full compromise of managed endpoints, lateral movement, and deployment of malicious software across the enterprise.
MITRE ATT&CK
LogScale Detection Query
#event_simpleName IN ("NetworkConnectIP4", "NetworkConnectIP6", "UserLogon", "UserLogonFailed")
| $falcon.metadata.eventType = "NetworkConnectIP4" OR $falcon.metadata.eventType = "UserLogon"
NetworkConnectIP4
| RemotePort IN (9675, 9676)
OR (ImageFileName IMATCH "landesk|ivanti|epm|cba8|lddiscovery")
| rename RemoteAddressIP4 AS target_ip, LocalAddressIP4 AS src_ip
| join type=inner [
UserLogon
| UserName = "" OR UserName IMATCH "anonymous|guest"
| AuthenticationPackage != "Kerberos"
| LogonType IN (3, 10)
| fields ComputerName, UserName, UserSid, RemoteAddressIP4, LogonType, AuthenticationPackage
] on ComputerName
| eval bypass_type = case(
UserName = "", "empty_username_logon",
UserName IMATCH "anonymous", "anonymous_logon",
UserName IMATCH "guest", "guest_logon",
true(), "other_suspicious"
)
| stats count() AS event_count, values(bypass_type) AS bypass_types, min(timestamp) AS first_seen, max(timestamp) AS last_seen
BY ComputerName, src_ip, target_ip, UserName, ImageFileName
| where event_count >= 1
| sort - event_countCrowdStrike Falcon LogScale (CQL) query correlating network connections to Ivanti EPM ports and processes with anomalous user logon events featuring empty, anonymous, or guest usernames, indicating potential CVE-2026-1603 authentication bypass exploitation.
Data Sources
Required Tables
False Positives & Tuning
- CrowdStrike sensor telemetry gaps where username fields are not populated during certain logon types
- Authorized EPM agents or service accounts using non-Kerberos authentication methods in legacy environments
- Vulnerability scanning or penetration testing tools exercising EPM authentication endpoints with authorized credentials
- EPM agent provisioning workflows that temporarily authenticate with reduced or empty credentials during initial enrollment
Other platforms for CVE-2026-1603
Testing Methodology
Validate this detection against 3 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.
- Test 1Simulate Anonymous Network Logon to EPM Port
Expected signal: Windows Security EventID 4624 with LogonType=3 and AccountName blank or 'ANONYMOUS LOGON' on the EPM server; IIS access log entry with 401/200 status for /ldlogon/ from test source IP; network flow record on EPM management port 9675.
- Test 2EPM Process Spawning Suspicious Child Process
Expected signal: DeviceProcessEvents entry showing cmd.exe spawned with working directory in Ivanti Management Suite path; process creation event with parent process in EPM directory; command line containing 'whoami' captured in endpoint telemetry.
- Test 3Authentication Bypass Simulation via Empty Credential HTTP Request
Expected signal: IIS access log entry on EPM server showing request to /ldlogon/ with empty Authorization header from test IP; network flow record; if EPM processes the request, a Windows Security EventID 4624 or 4648 with minimal credential context.
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