Full Report
The web server login page of affected products does not apply proper origin checking. This could allow authenticated remote attackers to track the activities of other users via a login cross-site request forgery attack.. Siemens has released updates for several affected products and recommends to update to the latest versions. Siemens recommends specific countermeasures for products where updates are not, or not yet available.
Analysis Summary
# Vulnerability: Missing CSRF Protection in Web Server Login Pages Leading to User Activity Tracking
## CVE Details
- CVE ID: Not explicitly provided in the summary text, but implied by the advisory SSA-478960. (Note: A comprehensive security advisory usually includes a CVE, but one is omitted here.)
- CVSS Score: 6.5 (Medium)
- CWE: CWE-352: Cross-Site Request Forgery (CSRF)
## Affected Systems
- Products: Various Siemens SIMATIC controllers and related software, including but not limited to:
- SIMATIC Drive Controller CPU 1504D TF (6ES7615-4DF10-0AB0)
- SIMATIC S7-300 CPUs (314C-2 PN/DP, 315-2 PN/DP, 315F-2 PN/DP, 315T-3 PN/DP, 317-2 PN/DP, 317F-2 PN/DP, 317T-3 PN/DP, 317TF-3 PN/DP, 319-3 PN/DP, 319F-3 PN/DP)
- SINUMERIK ONE (affects integrated SIMATIC S7-1500 CPU)
- SIMATIC ET 200SP Open Controller CPU 1515SP PC2 (incl. SIPLUS variants)
- Versions: Specific vulnerable versions vary by product family (e.g., All versions earlier than specified patch versions like V2.1, V3.3.19, V3.2.19, etc.)
- Configurations: Affects products with the web server login interface enabled for the `/FormLogin` endpoint.
## Vulnerability Description
The web server login endpoint (`/FormLogin`) in the affected products fails to implement proper origin checking. This weakness allows an authenticated remote attacker to exploit the flaw via a Cross-Site Request Forgery (CSRF) attack. Successful exploitation could enable the attacker to track the activities of other users accessing the web interface.
## Exploitation
- Status: PoC available (Implied by CVSS E:P - Proof-of-Concept)
- Complexity: Low (AC:L - Attack Complexity Low)
- Attack Vector: Network (AV:N)
## Impact
- Confidentiality: High (C:H) - The ability to track other user's activities implies potential access to sensitive session or operational data.
- Integrity: None (I:N)
- Availability: None (A:N)
## Remediation
### Patches
Siemens has released updates for several affected products. Users should update to the versions listed below or later, or consult the advisory for the specific fix version for their product:
* **SIMATIC S7-300 (most listed CPUs):** Update to version **V3.2.19 or later**.
* **SIMATIC S7-300 CPU 314C-2 PN/DP:** Update to version **V3.3.19 or later**.
* **SIMATIC Drive Controller CPU 1504D TF:** Fix is available starting from V2.9.7 (Note: Initial advisory indicated no fix planned, but later updates provided fixes).
* **Other impacted products** (e.g., SINUMERIK ONE, SIMATIC S7-1500 families, WinCC Runtime Advanced) require checking the full advisory for corresponding patched versions.
### Workarounds
For products where updates are not yet available:
1. **Disable the Web Server:** This feature is noted as disabled by default for the SIMATIC Drive Controller CPU 1504D TF. Disabling the web server eliminates the attack surface.
2. Consult section "[Workarounds and Mitigations](https://cert-portal.siemens.com/productcert/html/ssa-478960.html#mitigations-section)" in the original Siemens advisory for further product-specific countermeasures.
## Detection
- **Indicators of Compromise (IoCs):** Monitoring web server logs for unexpected requests to the `/FormLogin` endpoint originating from unexpected domains or hosts, especially when associated with user session activity tracking.
- **Detection Methods and Tools:** Utilize Web Application Firewalls (WAFs) or network monitoring tools to detect requests lacking expected CSRF tokens or proper `Origin` headers, specifically targeting authentication or state-changing endpoints if the general fix is not applied.
## References
- Siemens Security Advisory SSA-478960 (Publication Date: 2022-11-08, Last Update: 2023-09-12)
- Vendor Advisory Link: hxxps://cert-portal.siemens.com/productcert/html/ssa-478960.html