Full Report
APOGEE PXC / TALON TC field panels (BACnet before V3.5.5 and P2 Ethernet before V2.8.20) contain multiple vulnerabilities: CVE-2022-45937: A privilege management vulnerability that could allow low privilege authenticated attackers to gain high privilege access. CVE-2020-28388: Predictable Initial Sequence Numbers in the TCP/IP Stack of Nucleus RTOS (real-time operating system) used by the affected products. Several vulnerabilities in the DNS (domain name service) implementation of Nucleus RTOS. Siemens has released updates for the affected products and recommends to update to the latest versions.
Analysis Summary
# Vulnerability: Privilege Management & Nucleus RTOS Flaws in APOGEE/TALON Field Panels
## CVE Details
- CVE ID: CVE-2022-45937
- CVSS Score: 8.8 (High)
- CWE: CWE-284: Improper Access Control
- CVE ID: CVE-2020-28388
- CVSS Score: Not explicitly provided for this CVE alone in the summary, but related Nucleus RTOS vulnerabilities are severe.
- CWE: Not explicitly provided for this CVE alone in the summary, but related to Predictable Initial Sequence Numbers.
(Note: Other Nucleus RTOS vulnerabilities are mentioned, such as CVE-2020-15795 (8.1), CVE-2020-27009 (8.1), and CVE-2020-27736 (5.3), but the primary focus based on the description seems to be on CVE-2022-45937 and CVE-2020-28388.)
## Affected Systems
- Products: APOGEE PXC Compact/Modular Series, TALON TC Compact/Modular Series Field Panels.
- Versions:
- BACnet instances: All versions **before V3.5.5**.
- P2 Ethernet instances: All versions **before V2.8.20**.
- Configurations: Direct Digital Control (DDC) devices integrated into APOGEE or TALON Automation Systems.
## Vulnerability Description
The advisory covers multiple flaws stemming from the affected products utilizing the Nucleus RTOS:
1. **CVE-2022-45937 (Privilege Management Flaw):** A vulnerability in the integrated web server allows a low-privilege, authenticated attacker with network access to download sensitive information, specifically containing user account credentials, potentially leading to privilege escalation.
2. **CVE-2020-28388 (Nucleus RTOS):** Predictable Initial Sequence Numbers (ISNs) within the TCP/IP stack of the embedded Nucleus RTOS.
3. **Other Nucleus RTOS Flaws:** Several vulnerabilities exist in the DNS implementation of Nucleus RTOS (e.g., issues related to parsing malformed responses leading to potential RCE or DoS).
## Exploitation
- Status: **Exploited in the wild** (Implied by the 'E:P' in associated CVSS vectors for dependent OS vulnerabilities, though for CVE-2022-45937 the Vector indicates 'E:P' - Proof-of-Concept available).
- Complexity: **Low** (For CVE-2022-45937, AV:N/PR:L/UI:N suggests low complexity for an already authenticated user).
- Attack Vector: Network (For network-facing elements like the web server and TCP/IP stack).
## Impact
| Metric | Impact Level |
| :--- | :--- |
| Confidentiality | High (CVE-2022-45937 allows downloading credentials) |
| Integrity | High (Implied by potential RCE from related Nucleus flaws) |
| Availability | High (Implied by potential DoS from related Nucleus flaws) |
## Remediation
### Patches
Siemens has released updates incorporating fixes for these vulnerabilities:
- Update BACnet versions to **V3.5.5 or later**.
- Update P2 Ethernet versions to **V2.8.20 or later**.
### Workarounds
1. Implement strong network access controls to protect affected products.
2. Follow general security recommendations provided by Siemens, which typically involve securing the IT environment where these devices operate.
## Detection
- **Indicators of Compromise:** Monitoring for abnormal network connections directed at the embedded web server interface, successful unauthorized logins, or unusual process behavior on the DDC devices (though specific IOCs are not detailed in this summary).
- **Detection Methods and Tools:** Network monitoring tools capable of inspecting traffic related to common BACnet/DDC protocols and system login attempts. Vulnerability scanners configured to identify product versions below the specified patch levels.
## References
- Vendor Advisories:
- Siemens Security Advisory SSA-180579
- Nucleus RTOS vulnerability details referenced in SSA-185699, SSA-705111, and SSA-362164.
- Relevant Links (Defanged):
- hxxps://cert-portal.siemens.com/productcert/html/ssa-180579.html
- hxxps://www.siemens.com/cert/advisories