Detect Versa Concerto Improper Authentication (CVE-2025-34026) in Sumo Logic CSE
Detects exploitation attempts targeting CVE-2025-34026, an improper authentication vulnerability (CWE-288) in Versa Concerto SD-WAN orchestration platform. This vulnerability allows attackers to bypass authentication controls, potentially enabling unauthorized access to the Concerto management interface. Listed as a CISA KEV, indicating active exploitation in the wild.
MITRE ATT&CK
Sumo Detection Query
_sourceCategory=network/web OR _sourceCategory=proxy OR _sourceCategory=firewall
| where %"cs-host" matches "*concerto*" or %"cs-host" matches "*versa*" or _sourceHost matches "*concerto*" or _sourceHost matches "*versa*"
| parse regex field=_raw "\"(?P<http_method>GET|POST|PUT|DELETE|PATCH|OPTIONS)\s+(?P<uri_path>/[^\s]+)"
| parse regex field=_raw "HTTP/[0-9\.]+\"\s+(?P<status_code>[0-9]{3})"
| parse regex field=_raw "user=(?P<username>[^\s&]+)" nodrop
| where uri_path matches "*/api/*" or uri_path matches "*/auth*" or uri_path matches "*/admin*" or uri_path matches "*/management*"
| where status_code = "200"
| where isBlank(username) or username = "-" or toLowerCase(username) = "anonymous"
| count by _sourceHost, src_ip, uri_path, http_method, status_code, username
| sort by _count descSumo Logic query detecting unauthenticated successful access to protected Versa Concerto management endpoints. Parses web access logs to flag HTTP 200 responses to sensitive paths where no authenticated user is identified.
Data Sources
Required Tables
False Positives & Tuning
- Load balancer or reverse proxy health checks that appear as anonymous requests
- Token-authenticated API clients where user field is not reflected in access logs
- Internal microservices communicating with Concerto API without user context
- Authorized penetration testing activity against Versa infrastructure
Other platforms for CVE-2025-34026
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.
- Test 1Unauthenticated GET to Versa Concerto API Endpoint
Expected signal: HTTP access log on Concerto server showing GET /api/v1/system/info with source IP of test host, status 200, and empty/anonymous username field. Network flow showing connection to port 443.
- Test 2Authentication Bypass Probe via Malformed Auth Header
Expected signal: Series of HTTP requests to multiple protected paths logged on Concerto host. Network proxy logs showing path enumeration pattern from single source IP within short time window.
- Test 3Post-Authentication-Bypass Configuration Read
Expected signal: HTTP GET to /api/v1/vnf/inventory logged with 200 response and response body size. DLP or data exfiltration alerts if JSON response contains sensitive topology data. Network flow showing data transfer volume.
- Test 4Concerto Admin User Creation via Unauthenticated API
Expected signal: HTTP POST to /api/v1/users logged. Concerto audit log entry for user creation event. If successful, new user visible in Concerto user management interface.
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