Detect CVE-2026-48558 — SimpleHelp Authentication Bypass (CWE-347) in IBM QRadar
Detects exploitation of CVE-2026-48558, an authentication bypass vulnerability in SimpleHelp remote support software caused by improper verification of cryptographic signatures (CWE-347). This KEV-listed vulnerability allows unauthenticated attackers to bypass authentication controls. SimpleHelp is commonly used by MSPs and IT support teams, making it a high-value target for initial access and lateral movement.
MITRE ATT&CK
QRadar Detection Query
SELECT
sourceip,
destinationip,
destinationport,
URL,
username,
"HTTP Response Code" AS http_status,
"HTTP Method" AS http_method,
LOGSOURCENAME(logsourceid) AS log_source,
starttime,
endtime,
COUNT(*) AS request_count
FROM events
WHERE
LOGSOURCETYPENAME(devicetype) IN ('Apache HTTP Server', 'Microsoft IIS', 'Nginx', 'Juniper WebApp Secure')
AND (
URL ILIKE '%/admin%'
OR URL ILIKE '%/operator%'
OR URL ILIKE '%/technician%'
OR URL ILIKE '%/api/admin%'
)
AND "HTTP Response Code" IN (200, 302)
AND (username IS NULL OR username = '-' OR username = '')
AND LAST 7 DAYS
GROUP BY sourceip, destinationip, destinationport, URL, username, http_status, http_method, log_source
HAVING request_count >= 1
ORDER BY request_count DESCQRadar AQL query detecting unauthenticated successful HTTP responses from SimpleHelp privileged endpoints. Absence of username field combined with HTTP 200/302 on admin paths indicates authentication bypass.
Data Sources
Required Tables
False Positives & Tuning
- Web application firewalls or reverse proxies that do not propagate username fields in forwarded logs
- Internal IT support staff accessing SimpleHelp from trusted network segments
- Automated service account access where credentials are not logged by the web server
- QRadar log source configurations that do not parse authentication fields from SimpleHelp logs
Other platforms for CVE-2026-48558
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 1CVE-2026-48558 — Unauthenticated Admin Endpoint Access Probe
Expected signal: Web server access logs will show GET requests to /admin, /operator, /technician, and /api/admin from the test host IP. Network flow data will show connections from test host to SimpleHelp port. IDS/IPS may generate HTTP policy violation alerts.
- Test 2CVE-2026-48558 — Signature Verification Bypass via Malformed Token
Expected signal: Application logs should show authentication attempts with malformed tokens. Web server logs will record requests with Authorization headers containing invalid credentials. Endpoint detection may flag the curl process making connections to internal services.
- Test 3CVE-2026-48558 — Post-Bypass Operator Account Enumeration
Expected signal: Multiple sequential API requests to /api/admin/* paths from single source IP within short timeframe. Application logs show operator/technician/config endpoint access. UEBA tools may flag unusual API access patterns if baselining is in place.
References (4)
- https://simple-help.com/security/simplehelp-security-update-2026-05
- https://www.cisa.gov/news-events/directives/bod-26-04-prioritizing-security-updates-based-risk
- https://www.cisa.gov/news-events/directives/bod-26-04-implementation-guidance-prioritizing-security-updates-based-risk
- https://nvd.nist.gov/vuln/detail/CVE-2026-48558
Unlock Pro Content
Get the full detection package for CVE-2026-48558 including response playbook, investigation guide, and atomic red team tests.