Authentication Bypass Vulnerability in SINEC NMS

Plan PatchCVSS 7.3SSA-801704Apr 14, 2026
Siemens
Attack path
Attack VectorNetwork
Auth RequiredNone
ComplexityLow
User InteractionNone needed
Summary

SINEC NMS with User Management Component (UMC) contains an authentication bypass vulnerability due to insufficient validation of user identity. An unauthenticated remote attacker could bypass authentication and gain unauthorized access to the application.

What this means
What could happen
An attacker could bypass login authentication on your SINEC NMS and gain full administrative access to your network management system, potentially allowing them to modify network configurations, view sensitive data, or disrupt monitoring of your industrial network.
Who's at risk
Network operations and infrastructure teams managing Siemens SINEC NMS deployments for industrial network monitoring and management. This impacts any organization using SINEC NMS with the User Management Component feature.
How it could be exploited
An attacker on the network sends a specially crafted request to the SINEC NMS application that bypasses the authentication check in the User Management Component. With no valid credentials needed, they gain direct access to the management interface and its functions.
Prerequisites
  • Network access to the SINEC NMS application port
  • SINEC NMS version below V4.0 SP3 with User Management Component (UMC) enabled
remotely exploitableno authentication requiredlow complexityaffects network management systems
Exploitability
Unlikely to be exploited — EPSS score 0.1%
Affected products (1)
ProductAffected VersionsFix Status
SINEC NMSAll versions < V4.0 SP3 with UMC4.0 SP3
Remediation & Mitigation
0/1
Schedule — requires maintenance window
0/1

Patching may require device reboot — plan for process interruption

HOTFIXUpdate SINEC NMS to version V4.0 SP3 or later
API: /api/v1/advisories/29c0708c-dc87-4c2a-9736-ef51c69a780a

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Authentication Bypass Vulnerability in SINEC NMS | CVSS 7.3 - OTPulse