Full Report
Mendix Runtime contains an observable response discrepancy vulnerability when validating usernames during authentication. This could allow unauthenticated remote attackers to distinguish between valid and invalid usernames. Siemens has released new versions for the affected products and recommends to update to the latest versions.
Analysis Summary
# Vulnerability: Mendix Runtime Observable Response Discrepancy in Username Validation
## CVE Details
- CVE ID: CVE-2023-49069
- CVSS Score: 5.3 (CVSS v3.1) / 6.9 (CVSS v4.0) (Medium)
- CWE: CWE-204: Observable Response Discrepancy
## Affected Systems
- Products: Mendix Runtime (V8, V9, V10, and potentially others using the affected authentication mechanism)
- Versions: All versions of affected Mendix Runtime lines (specific fix information is listed under Remediation)
- Configurations: Applications utilizing the standard username validation during authentication.
## Vulnerability Description
The authentication mechanism within the Mendix Runtime suffers from an observable response discrepancy when validating usernames. This flaw allows an unauthenticated, remote attacker to observe differences in the system's response based on whether a provided username is valid or invalid. This difference enables the attacker to brute-force or enumerate valid usernames.
## Exploitation
- Status: Not explicitly stated as exploited in the wild, but the vulnerability is technically feasible.
- Complexity: Low (AC:L, PR:N, AV:N based on CVSS 3.1 vector implies low effort for an unauthenticated network attack).
- Attack Vector: Network
## Impact
- Confidentiality: Low (Information disclosure: ability to identify valid usernames)
- Integrity: No impact expected.
- Availability: No impact expected.
## Remediation
### Patches
Siemens strongly recommends updating to the latest product versions incorporating the fix for CVE-2023-49069. Specific fix releases were sequentially provided for Mendix Runtime V8, V9, and V10 lines. Users must review the official advisory for the precise fixed versions applicable to their installed lines (e.g., Mendix Runtime V10.12 and V10.6 have received complete patches).
### Workarounds
1. **General Security Recommendations:** Protect network access to devices using appropriate mechanisms and adhere to Siemens' operational guidelines for Industrial Security.
2. **Authentication Hardening (for REST/Web/oData APIs):** For published REST, web services, and oData APIs: Do not use basic authentication. Instead, use Custom or Active Session authentication methods.
## Detection
- Indicators of compromise: No specific IoCs detailed, but look for a high volume of authentication attempts querying different/sequential usernames by an unauthenticated source.
- Detection methods and tools: Monitoring authentication endpoints for unusual patterns indicative of username enumeration attempts.
## References
- Vendor advisories: SSA-097435
- Relevant links - defanged: hxxps://cert-portal.siemens.com/productcert/html/ssa-097435.html