Full Report
Siemens User Management Component (UMC) is affected by a heap-based buffer overflow vulnerability which could allow an unauthenticated remote attacker arbitrary code execution. Siemens has released new versions for several affected products and recommends to update to the latest versions. Siemens recommends specific countermeasures for products where fixes are not, or not yet available.
Analysis Summary
# Vulnerability: Heap-based Buffer Overflow in Siemens User Management Component (UMC)
## CVE Details
- **CVE ID:** CVE-2024-49775
- **CVSS Score:** 9.8 (Critical) [CVSS v3.1] / 9.3 (Critical) [CVSS v4.0]
- **CWE:** CWE-122: Heap-based Buffer Overflow
## Affected Systems
- **Products:** Various Siemens industrial software utilizing the integrated User Management Component (UMC).
- **Versions:**
- **Opcenter Execution Foundation:** All versions < V2501.0001
- **Opcenter Intelligence:** All versions < V2501.0001
- **Opcenter Quality:** All versions < V2512
- **Opcenter RDnL:** All versions < V2410
- **SIMATIC PCS neo V4.0:** All versions
- **SIMATIC PCS neo V4.1:** All versions < V4.1 Update 3
- **SIMATIC PCS neo V5.0:** All versions < V5.0 Update 1
- **SINEC NMS:** All versions when used with UMC < V2.15
- **TIA Portal V16:** All versions
- **TIA Portal V17, V18, V19:** (Affected, specific fix versions available)
- **Configurations:** Systems where UMC is used for plant-wide central maintenance of users or integrated with Microsoft Active Directory.
## Vulnerability Description
The integrated User Management Component (UMC) contains a heap-based buffer overflow flaw. This vulnerability occurs when the application writes more data to a heap-allocated memory buffer than the buffer can hold, leading to memory corruption. An attacker can exploit this to overwrite adjacent memory structures, potentially altering program execution flow.
## Exploitation
- **Status:** Coordinated disclosure by Tenable; no current reports of exploitation in the wild.
- **Complexity:** Low
- **Attack Vector:** Network (Remote)
## Impact
- **Confidentiality:** High (Full access to data)
- **Integrity:** High (Arbitrary code execution)
- **Availability:** High (System crash or complete takeover)
## Remediation
### Patches
Siemens recommends updating to the following versions or later:
- **Opcenter Execution Foundation:** V2501.0001
- **Opcenter Intelligence:** V2501.0001
- **Opcenter Quality:** V2512
- **Opcenter RDnL:** V2410
- **SIMATIC PCS neo V4.1:** V4.1 Update 3
- **SIMATIC PCS neo V5.0:** V5.0 Update 1
- **SINEC NMS:** Update UMC to V2.15.1.1
- **TIA Portal:** Update to V20 (which incorporates a fixed UMC version)
### Workarounds
For products where no fix is currently planned (e.g., SIMATIC PCS neo V4.0, TIA Portal V16):
- Follow general "Mitigations" section guidance in the Siemens advisory.
- Restrict network access to the UMC component to trusted IP addresses only.
- Implement defense-in-depth security concepts.
## Detection
- **Indicators of Compromise:** Unusual crashes of the UMC service or unexpected administrative account creations.
- **Detection methods and tools:** Monitoring for malformed network traffic targeting UMC ports; utilizing vulnerability scanners (e.g., Tenable) to identify vulnerable versions of Siemens software.
## References
- **Vendor Advisory:** [https://cert-portal.siemens.com/productcert/html/ssa-928984.html](https://cert-portal.siemens.com/productcert/html/ssa-928984.html)
- **Siemens CERT:** [https://www.siemens.com/cert/advisories](https://www.siemens.com/cert/advisories)