OTPulse

Account Hijacking Vulnerability in Mendix SAML Module

Plan PatchCVSS 8.7SSA-395458Aug 14, 2025
Siemens
Attack path
Attack VectorNetwork
Auth RequiredNone
ComplexityHigh
User InteractionNone needed
Summary

Mendix SAML module contains a vulnerability in SAML authentication handling that allows unauthenticated remote attackers to hijack user accounts when using specific SSO configurations. An attacker could establish an authenticated session as a legitimate user without knowing credentials. Affected versions are Mendix SAML module versions prior to 3.6.21 (Mendix 9.24), 4.0.3 (Mendix 10.12), and 4.1.2 (Mendix 10.21).

What this means
What could happen
An attacker could hijack user accounts in Mendix applications using SSO authentication without knowing user credentials, potentially gaining access to sensitive data or process control functions.
Who's at risk
Organizations using Mendix applications with SAML-based single sign-on (SSO) for user authentication. This includes utility automation platforms, engineering workstations, and web-based operator interfaces that rely on Mendix for application development and deployment.
How it could be exploited
An attacker sends a crafted request to the Mendix SAML module that bypasses authentication verification, impersonating a legitimate user and obtaining an authenticated session. The attack requires specific SAML configurations but no user interaction.
Prerequisites
  • Network access to the Mendix application
  • Application must be using Mendix SAML module for SSO
  • Specific SAML configuration settings must be present
remotely exploitablehigh CVSS score (8.7)no authentication requiredaffects identity and access control
Exploitability
Unlikely to be exploited — EPSS score 0.0%
Affected products (3)
3 with fix
ProductAffected VersionsFix Status
Mendix SAML (Mendix 9.24 compatible)< 3.6.213.6.21
Mendix SAML (Mendix 10.12 compatible)< 4.0.34.0.3
Mendix SAML (Mendix 10.21 compatible)< 4.1.24.1.2
Remediation & Mitigation
0/4
Do now
0/1
HARDENINGReview SAML configuration settings in affected applications to identify if your configuration matches the vulnerable pattern
Schedule — requires maintenance window
0/3

Patching may require device reboot — plan for process interruption

Mendix SAML (Mendix 9.24 compatible)
HOTFIXUpdate Mendix SAML module to version 3.6.21 or later (for Mendix 9.24 compatible installations)
Mendix SAML (Mendix 10.12 compatible)
HOTFIXUpdate Mendix SAML module to version 4.0.3 or later (for Mendix 10.12 compatible installations)
Mendix SAML (Mendix 10.21 compatible)
HOTFIXUpdate Mendix SAML module to version 4.1.2 or later (for Mendix 10.21 compatible installations)
View full Siemens ProductCERT advisory
API: /api/v1/advisories/86218c0e-5b98-46c5-8710-26cf9533d1a5

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Account Hijacking Vulnerability in Mendix SAML Module | CVSS 8.7 - OTPulse