https://cert-portal.siemens.com/productcert/pdf/ssa-044112.pdf

https://cert-portal.siemens.com/productcert/pdf/ssa-114589.pdf

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 MKD/XMKD command, leading to stack-based buffer overflows. This may result in Denial-of-Service conditions and Remote Code Execution. (FSMD-2021-0018)

This plugin only works with Tenable.ot.
Please visit https://www.tenable.com/products/tenable-ot for more information.

A FTP server running on the remote host is possibly affected by multiple vulnerabilities : 

  - 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.
    (CVE-2021-31886)

  - FTP server does not properly validate the length of the PWD/XPWD     command, leading to stack-based buffer overflows. This may result     in denial-of-service conditions and remote code execution.
    (CVE-2021-31887) 

  - FTP server does not properly validate the length of the MKD/XMKD     command, leading to stack-based buffer overflows. This may result     in denial-of-service conditions and remote code execution.
    (CVE-2021-31888)

Note that Nessus reports these vulnerabilities based on the presence of the Nucleus FTP server. These vulnerabilities might have been mitigated.

ID	Name	Product	Family	Severity
500564	Siemens (CVE-2021-31888)	Tenable.ot	Tenable.ot	high
155154	Nucleus FTP Server Multiple Vulnerabilities (NUCLEUS:13)	Nessus	SCADA	critical

CVE-2021-31888

high

Tenable Plugins

high

critical