Vulnerability Monitor

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CVE-2021-31886


A vulnerability has been identified in APOGEE MBC (PPC) (BACnet) (All versions), APOGEE MBC (PPC) (P2 Ethernet) (All versions), APOGEE MEC (PPC) (BACnet) (All versions), APOGEE MEC (PPC) (P2 Ethernet) (All versions), APOGEE PXC Compact (BACnet) (All versions < V3.5.4), APOGEE PXC Compact (P2 Ethernet) (All versions < V2.8.19), APOGEE PXC Modular (BACnet) (All versions < V3.5.4), APOGEE PXC Modular (P2 Ethernet) (All versions < V2.8.19), Desigo PXC00-E.D (All versions >= V2.3 and < V6.30.016), Desigo PXC00-U (All versions >= V2.3 and < V6.30.016), Desigo PXC001-E.D (All versions >= V2.3 and < V6.30.016), Desigo PXC100-E.D (All versions >= V2.3 and < V6.30.016), Desigo PXC12-E.D (All versions >= V2.3 and < V6.30.016), Desigo PXC128-U (All versions >= V2.3 and < V6.30.016), Desigo PXC200-E.D (All versions >= V2.3 and < V6.30.016), Desigo PXC22-E.D (All versions >= V2.3 and < V6.30.016), Desigo PXC22.1-E.D (All versions >= V2.3 and < V6.30.016), Desigo PXC36.1-E.D (All versions >= V2.3 and < V6.30.016), Desigo PXC50-E.D (All versions >= V2.3 and < V6.30.016), Desigo PXC64-U (All versions >= V2.3 and < V6.30.016), Desigo PXM20-E (All versions >= V2.3 and < V6.30.016), Nucleus NET (All versions), Nucleus ReadyStart V3 (All versions < V2017.02.4), Nucleus Source Code (All versions), TALON TC Compact (BACnet) (All versions < V3.5.4), TALON TC Modular (BACnet) (All versions < V3.5.4). FTP server does not properly validate the length of the “USER” command, leading to stack-based buffer overflows. This may result in Denial-of-Service conditions and Remote Code Execution. (FSMD-2021-0010)


Security Impact Summary

This vulnerability carries a CRITICAL severity rating with a CVSS v3.1 score of 9.8, indicating it can be exploited remotely over the network with relatively low complexity without requiring user interaction and does not require pre-existing privileges . The vulnerability impacts confidentiality (data exposure), integrity (unauthorized modifications), and availability (service disruption) for affected systems. Impacting 41 products from siemens, from siemens, from siemens and 38 others, organizations running these solutions should prioritize assessment and patching.

Historical Context

Reported in 2021, this vulnerability emerged during an era marked by increased sophistication in supply chain attacks, cloud infrastructure vulnerabilities, and software-as-a-service (SaaS) security challenges. Security practices during this period emphasized zero-trust architectures, container security, and API protection.


Published

2021-11-09T12:15:09.540

Last Modified

2024-11-21T06:06:25.880

Status

Modified

Source

[email protected]

Severity

CVSSv3.1: 9.8 (CRITICAL)

CVSSv2 Vector

AV:N/AC:L/Au:N/C:P/I:P/A:P

  • Access Vector: NETWORK
  • Access Complexity: LOW
  • Authentication: NONE
  • Confidentiality Impact: PARTIAL
  • Integrity Impact: PARTIAL
  • Availability Impact: PARTIAL
Exploitability Score

10.0

Impact Score

6.4

Weaknesses
  • Type: Secondary
    CWE-170
  • Type: Secondary
    CWE-787

Affected Vendors & Products
Type Vendor Product Version/Range Vulnerable?
Application siemens nucleus_net * Yes
Application siemens nucleus_readystart_v3 < 2017.02.4 Yes
Application siemens nucleus_source_code * Yes
Operating System siemens apogee_modular_building_controller_firmware * Yes
Hardware siemens apogee_modular_building_controller - No
Operating System siemens apogee_modular_equiment_controller_firmware * Yes
Hardware siemens apogee_modular_equiment_controller - No
Operating System siemens apogee_pxc_compact_firmware < 2.8.19 Yes
Operating System siemens apogee_pxc_compact_firmware < 3.5.4 Yes
Hardware siemens apogee_pxc_compact - No
Operating System siemens apogee_pxc_modular_firmware < 2.8.19 Yes
Operating System siemens apogee_pxc_modular_firmware < 3.5.4 Yes
Hardware siemens apogee_pxc_modular - No
Operating System siemens talon_tc_compact_firmware < 3.5.4 Yes
Hardware siemens talon_tc_compact - No
Operating System siemens talon_tc_modular_firmware < 3.5.4 Yes
Hardware siemens talon_tc_modular - No
Operating System siemens desigo_pxc00-e.d_firmware < 6.30.016 Yes
Hardware siemens desigo_pxc00-e.d - No
Operating System siemens desigo_pxc00-u_firmware < 6.30.016 Yes
Hardware siemens desigo_pxc00-u - No
Operating System siemens desigo_pxc001-e.d_firmware < 6.30.016 Yes
Hardware siemens desigo_pxc001-e.d - No
Operating System siemens desigo_pxc12-e.d_firmware < 6.30.016 Yes
Hardware siemens desigo_pxc12-e.d - No
Operating System siemens desigo_pxc22-e.d_firmware < 6.30.016 Yes
Hardware siemens desigo_pxc22-e.d - No
Operating System siemens desigo_pxc22.1-e.d_firmware < 6.30.016 Yes
Hardware siemens desigo_pxc22.1-e.d - No
Operating System siemens desigo_pxc36.1-e.d_firmware < 6.30.016 Yes
Hardware siemens desigo_pxc36.1-e.d - No
Operating System siemens desigo_pxc50-e.d_firmware < 6.30.016 Yes
Hardware siemens desigo_pxc50-e.d - No
Operating System siemens desigo_pxc64-u_firmware < 6.30.016 Yes
Hardware siemens desigo_pxc64-u - No
Operating System siemens desigo_pxc100-e.d_firmware < 6.30.016 Yes
Hardware siemens desigo_pxc100-e.d - No
Operating System siemens desigo_pxc128-u_firmware < 6.30.016 Yes
Hardware siemens desigo_pxc128-u - No
Operating System siemens desigo_pxc200-e.d_firmware < 6.30.016 Yes
Hardware siemens desigo_pxc200-e.d - No
Operating System siemens desigo_pxm20-e_firmware < 6.30.016 Yes
Hardware siemens desigo_pxm20-e - No

References

How SecUtils Interprets This CVE

SecUtils normalizes and enriches National Vulnerability Database (NVD) records by standardizing vendor and product identifiers, aggregating vulnerability metadata from both NVD and MITRE sources, and providing structured context for security teams. For siemens's affected products, we extract Common Platform Enumeration (CPE) data, Common Weakness Enumeration (CWE) classifications, CVSS severity metrics, and reference data to enable rapid vulnerability prioritization and asset correlation. This record contains no exploit code, proof-of-concept instructions, or attack methodologies—only defensive intelligence necessary for patch management, risk assessment, and security operations.