Detect Check Point Security Gateway Improper Authentication (CVE-2026-50751) in IBM QRadar
Detects exploitation of CVE-2026-50751, an improper authentication vulnerability (CWE-287) in Check Point Security Gateway affecting deprecated IKEv1 VPN protocol. This vulnerability is actively exploited in the wild (CISA KEV) and may allow unauthenticated attackers to bypass authentication controls on the VPN gateway. Detection focuses on anomalous IKEv1 negotiation patterns, authentication bypass indicators, and suspicious gateway access following failed or malformed IKE exchanges.
MITRE ATT&CK
- Tactic
- Initial Access Credential Access
QRadar Detection Query
SELECT sourceip, destinationip, devicename, QIDNAME(qid) AS event_name, UTF8(payload) AS raw_payload, starttime, eventcount
FROM events
WHERE LOGSOURCETYPENAME(logsourceid) ILIKE '%Check Point%'
AND (
UTF8(payload) ILIKE '%IKEv1%'
OR UTF8(payload) ILIKE '%aggressive mode%'
OR UTF8(payload) ILIKE '%ikev1%'
OR (UTF8(payload) ILIKE '%authentication%' AND UTF8(payload) ILIKE '%fail%')
OR UTF8(payload) ILIKE '%bypass%'
)
AND destinationport IN (500, 4500)
GROUP BY sourceip, devicename, EXTRACT(EPOCH FROM starttime) / 300
HAVING COUNT(*) > 2
ORDER BY eventcount DESC
LAST 1 HOURSQRadar AQL query detecting suspicious IKEv1 and authentication-related events from Check Point Security Gateway log sources, grouped by source IP in 5-minute windows to surface burst exploitation patterns.
Data Sources
Required Tables
False Positives & Tuning
- High-volume site-to-site VPN renegotiations from legitimate peer gateways
- Misconfigured VPN clients sending repeated IKEv1 proposals
- Security scanners running IKEv1 enumeration as part of authorized assessments
Other platforms for CVE-2026-50751
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 1IKEv1 Aggressive Mode Probe — Check Point Gateway
Expected signal: Check Point SmartLog IKE phase 1 event with protocol IKEv1, mode aggressive, from the test host IP. UDP/500 connection event in network logs.
- Test 2Repeated IKEv1 Auth Failure Simulation
Expected signal: 10 IKEv1 negotiation attempts with authentication failure events in SmartLog. Source IP flagged in Check Point IPS/firewall blade logs.
- Test 3IKEv1 vs IKEv2 Protocol Downgrade Attempt
Expected signal: StrongSwan IKEv1 initiation attempt visible in system logs; Check Point gateway logs showing inbound IKEv1 proposal from test host on UDP/500.
Unlock Pro Content
Get the full detection package for CVE-2026-50751 including response playbook, investigation guide, and atomic red team tests.