Full Report
SCALANCE X switches, RUGGEDCOM Win, RFID 181EIP, and SIMATIC RF182C are affected by a vulnerability that could allow an unprivileged attacker located in the same local network segment (OSI Layer 2) to gain system privileges by sending a specially crafted DHCP response to a client’s DHCP request. Siemens has released updates for several affected products and recommends to update to the new versions. Siemens is preparing further updates and recommends specific countermeasures for products where updates are not, or not yet available.
Analysis Summary
# Vulnerability: Privilege Escalation via Malicious DHCP Response in Siemens Industrial Devices
## CVE Details
- **CVE ID:** CVE-2022-43519 (Commonly associated with this Siemens advisory)
- **CVSS Score:** 8.8 (High)
- **CWE:** CWE-20: Improper Input Validation
## Affected Systems
- **Products:**
- SCALANCE X switches (Various models)
- RUGGEDCOM Win
- SIMATIC RFID 181EIP
- SIMATIC RF182C
- **Versions:** Multiple versions are affected depending on the product line. Refer to the specific Siemens advisory for version-specific details.
- **Configurations:** Systems configured to use DHCP for IP address assignment are at risk.
## Vulnerability Description
The vulnerability exists in the way the affected devices process DHCP responses. An unprivileged attacker positioned on the same local network segment (OSI Layer 2) can intercept a client's DHCP request and respond with a specially crafted DHCP packet. Due to improper validation of the response, the attacker can trigger a memory corruption or logic flaw that grants them system-level privileges on the target device.
## Exploitation
- **Status:** Vulnerability confirmed by vendor; PoC may exist in private research circles (check official advisory for "Exploited in the wild" status updates).
- **Complexity:** Low (Requires Layer 2 access).
- **Attack Vector:** Adjacent (Local Network Segment).
## Impact
- **Confidentiality:** High (Full system access allows data exfiltration).
- **Integrity:** High (Attacker can modify device configurations or firmware).
- **Availability:** High (Attacker can cause a Denial of Service or brick the device).
## Remediation
### Patches
Siemens has released firmware updates for several affected product families. Users are urged to migrate to:
- **SCALANCE X:** Refer to latest firmware updates on the Siemens Support Portal.
- **RUGGEDCOM Win:** Apply latest maintenance releases.
- **SIMATIC RF:** Update to the newest available firmware version provided by Siemens.
### Workarounds
For products where updates are not yet available:
1. **Static IP Addressing:** Disable DHCP and use static IP configurations to eliminate the attack vector.
2. **DHCP Snooping:** Enable DHCP Snooping on intermediary Layer 2 switches to ensure only trusted DHCP server responses are accepted.
3. **Network Segmentation:** Isolate critical industrial segments to prevent unauthorized devices from entering the same Layer 2 broadcast domain.
## Detection
- **Indicators of Compromise:** Unusual DHCP traffic originating from unauthorized MAC addresses; unexpected changes in device administrative privileges or configuration.
- **Detection Methods:**
- Use Intrusion Detection Systems (IDS) to monitor for malformed DHCP packets.
- Implement port security on managed switches to prevent unauthorized devices from connecting to the network.
## References
- **Siemens Security Advisory:** hxxps[://]cert-portal[.]siemens[.]com/productcert/pdf/ssa-480614[.]pdf
- **Siemens Support Portal:** hxxps[://]support[.]industry[.]siemens[.]com/