Full Report
SENTRON 3NA COM Fuse contains a Denial-of-Service vulnerability. Improper handling of a network management message could allow an attacker to trigger a denial-of-service (DoS) condition. Successful exploitation may require the affected network to be re-established to restore normal operation.
Analysis Summary
# Vulnerability: Denial of Service in SENTRON 3NA COM Fuse
## CVE Details
- **CVE ID:** CVE-2024-7322
- **CVSS Score:** 5.8 (Medium)
- **CVSS Vector:** CVSS:3.1/AV:N/AC:H/PR:H/UI:N/S:C/C:N/I:N/A:H
- **CWE:** CWE-940 (Improper Verification of Source of a Communication Channel)
## Affected Systems
- **Products:** SENTRON 3NA COM Fuse (NH fuse with current direction detection)
- **Versions:** All versions prior to V5.2
- **Configurations:** Devices acting as a ZigBee coordinator, router, or end device within the network.
## Vulnerability Description
The vulnerability stems from the improper handling of unsolicited encrypted rejoin responses within the ZigBee communication stack. If the device receives a specific network management message of this type, it may erroneously change its node ID. This unauthorized change results in a Denial-of-Service (DoS) condition for the affected device and potentially disrupts the wider communication chain.
## Exploitation
- **Status:** No reports of exploitation in the wild; no public PoC currently mentioned.
- **Complexity:** High (Exploitation requires specific conditions regarding network management messages and encryption).
- **Attack Vector:** Network (The attack is conducted over the communication network).
## Impact
- **Confidentiality:** None
- **Integrity:** None
- **Availability:** High (Loss of device functionality and potential requirement for a full network re-establishment to restore operations).
## Remediation
### Patches
- **Update to V5.2 or later:** Siemens has released version V5.2 to address this flaw. The update can be found at the following location:
- hxxps://support[.]industry[.]siemens[.]com/cs/ww/en/view/109797242/
### Workarounds
- **Network Segmentation:** Protect network access to devices using appropriate mechanisms to ensure they operate only within a protected IT/OT environment.
- **Operational Guidelines:** Adhere to Siemens' operational guidelines for Industrial Security.
- hxxps://www.siemens[.]com/cert/operational-guidelines-industrial-security
## Detection
- **Indicators of Compromise:** Unexpected changes in ZigBee node IDs; sudden loss of communication with SENTRON 3NA COM units that does not resolve without manual intervention.
- **Detection methods:** Monitoring ZigBee network management traffic for unsolicited rejoin responses; auditing device logs for node ID re-assignments.
## References
- **Siemens Security Advisory (SSA-099819):** hxxps://cert-portal[.]siemens[.]com/productcert/pdf/ssa-099819[.]pdf
- **Siemens Industrial Security Home:** hxxps://www.siemens[.]com/industrialsecurity