Full Report
Affected products do not properly sanitize user-controllable input when parsing files. This could allow an attacker to cause a type confusion and execute arbitrary code within the affected application. Siemens has released new versions for several affected products and recommends to update to the latest versions. Siemens is preparing further fix versions and recommends specific countermeasures for products where fixes are not, or not yet available. Siemens has released products based on the Totally Integrated Automation Portal (TIA Portal) V20 which are not affected by CVE-2024-49849. See the chapter “Additional Information” below for more details.
Analysis Summary
# Vulnerability: Deserialization and Type Confusion in Siemens Engineering Platforms
## CVE Details
- **CVE ID:** CVE-2024-49849
- **CVSS Score:** 7.8 (High) - CVSS v3.1 / 8.4 (High) - CVSS v4.0
- **CWE:** CWE-502 (Deserialization of Untrusted Data)
## Affected Systems
- **Products:**
- SIMATIC S7-PLCSIM (V16, V17)
- Totally Integrated Automation Portal (TIA Portal) (V16, V17, V18, V19)
- SIMATIC STEP 7 (Safety, WinCC, WinCC Unified) (V16, V17)
- SIMOCODE ES (V16)
- SINAMICS Startdrive (V16)
- TIA Portal Cloud (V16)
- SIMOTION SCOUT TIA (V5.4, V5.5, V5.6)
- **Versions:** All versions prior to TIA Portal V20 are generally affected unless specifically patched.
- **Configurations:** Systems where the application parses user-controllable log files or project files.
## Vulnerability Description
The affected Siemens engineering platforms do not properly sanitize user-controllable input when parsing specifically crafted files (notably log files). This lack of validation during the deserialization process allows an attacker to induce **Type Confusion**. This flaw can be leveraged to execute arbitrary code within the context of the affected application.
## Exploitation
- **Status:** PoC Available (Exploit Code Maturity: Functional/Proven per CVSS vector `E:P`).
- **Complexity:** Low
- **Attack Vector:** Local (Requires the user to open/parse a malicious file).
- **User Interaction:** Required (The user must be tricked into parsing a malicious file).
## Impact
- **Confidentiality:** High (Full access to application data)
- **Integrity:** High (Ability to modify application logic or system files)
- **Availability:** High (Potential for application crash or system takeover)
## Remediation
### Patches
Siemens recommends updating to **TIA Portal V20**, which is not affected by this vulnerability. Specific updates for older tracks include:
- **TIA Portal V17:** Update to V17 Update 9 or later.
- **TIA Portal V19:** Refer to the latest version/update released in August 2025.
- **V16 Versions:** No patches are currently planned for V16 product lines.
### Workarounds
For products where fixes are not yet available (such as V16), Siemens recommends the following:
- Limit the opening of untrusted files from unknown sources.
- Ensure the workstation operates under the principle of least privilege.
- Use "Defense in Depth" mechanisms, such as restricting access to engineering workstations to authorized personnel only.
## Detection
- **Indicators of Compromise:** Unusual application crashes during file imports or log parsing; unexpected outbound network traffic from engineering workstations; creation of unauthorized processes by `TIA Portal` or `S7-PLCSIM` executables.
- **Detection methods:** Monitor file system integrity for changes in engineering project directories. Use Endpoint Detection and Response (EDR) tools to flag anomalous child processes spawning from Siemens software suite components.
## References
- **Vendor Advisory:** [https://cert-portal.siemens.com/productcert/pdf/ssa-800126.pdf](https://cert-portal.siemens.com/productcert/pdf/ssa-800126.pdf)
- **Siemens ProductCERT:** [https://www.siemens.com/cert/advisories](https://www.siemens.com/cert/advisories)
- **TIA Portal V20 Info:** [https://support.industry.siemens.com/cs/document/109963850](https://support.industry.siemens.com/cs/document/109963850)