{"id":"CVE-2021-31887","aliases":["EUVD-2021-18762","GHSA-q5r7-v53q-5pgx"],"status":"published","title":"A vulnerability has been identified in APOGEE MBC (PPC) (BACnet) (All versions), APOGEE MBC (PPC)...","description":"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 \u003c V3.5.4), APOGEE PXC Compact (P2 Ethernet) (All versions \u003c V2.8.19), APOGEE PXC Modular (BACnet) (All versions \u003c V3.5.4), APOGEE PXC Modular (P2 Ethernet) (All versions \u003c V2.8.19), Desigo PXC00-E.D (All versions \u003e= V2.3 and \u003c V6.30.016), Desigo PXC00-U (All versions \u003e= V2.3 and \u003c V6.30.016), Desigo PXC001-E.D (All versions \u003e= V2.3 and \u003c V6.30.016), Desigo PXC100-E.D (All versions \u003e= V2.3 and \u003c V6.30.016), Desigo PXC12-E.D (All versions \u003e= V2.3 and \u003c V6.30.016), Desigo PXC128-U (All versions \u003e= V2.3 and \u003c V6.30.016), Desigo PXC200-E.D (All versions \u003e= V2.3 and \u003c V6.30.016), Desigo PXC22-E.D (All versions \u003e= V2.3 and \u003c V6.30.016), Desigo PXC22.1-E.D (All versions \u003e= V2.3 and \u003c V6.30.016), Desigo PXC36.1-E.D (All versions \u003e= V2.3 and \u003c V6.30.016), Desigo PXC50-E.D (All versions \u003e= V2.3 and \u003c V6.30.016), Desigo PXC64-U (All versions \u003e= V2.3 and \u003c V6.30.016), Desigo PXM20-E (All versions \u003e= V2.3 and \u003c V6.30.016), Nucleus NET (All versions), Nucleus ReadyStart V3 (All versions \u003c V2017.02.4), Nucleus Source Code (All versions), TALON TC Compact (BACnet) (All versions \u003c V3.5.4), TALON TC Modular (BACnet) (All versions \u003c V3.5.4). 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. (FSMD-2021-0016)","severity":{"version":"3.1","score":8.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","level":"high","assessor":"primary","from":"nvd"},"epss":{"day":"2026-11-12","score":0.02449,"percentile":0.84599,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-170","CWE-787"],"published":"2021-11-09T11:32:00Z","modified":"2026-06-17T03:52:25Z","products":[{"vendor":"siemens","product":"apogee mbc (ppc) (bacnet)"},{"vendor":"siemens","product":"apogee mbc (ppc) (p2 ethernet)"},{"vendor":"siemens","product":"apogee mec (ppc) (bacnet)"},{"vendor":"siemens","product":"apogee mec (ppc) (p2 ethernet)"},{"vendor":"siemens","product":"apogee pxc compact (bacnet)"},{"vendor":"siemens","product":"apogee pxc compact (p2 ethernet)"},{"vendor":"siemens","product":"apogee pxc modular (bacnet)"},{"vendor":"siemens","product":"apogee pxc modular (p2 ethernet)"},{"vendor":"siemens","product":"apogee_modular_building_controller_firmware"},{"vendor":"siemens","product":"apogee_modular_equiment_controller_firmware"},{"vendor":"siemens","product":"apogee_pxc_compact_firmware"},{"vendor":"siemens","product":"apogee_pxc_modular_firmware"},{"vendor":"siemens","product":"desigo pxc00-e.d"},{"vendor":"siemens","product":"desigo pxc00-u"},{"vendor":"siemens","product":"desigo pxc001-e.d"},{"vendor":"siemens","product":"desigo pxc100-e.d"},{"vendor":"siemens","product":"desigo pxc12-e.d"},{"vendor":"siemens","product":"desigo pxc128-u"},{"vendor":"siemens","product":"desigo pxc200-e.d"},{"vendor":"siemens","product":"desigo pxc22-e.d"},{"vendor":"siemens","product":"desigo pxc22.1-e.d"},{"vendor":"siemens","product":"desigo pxc36.1-e.d"},{"vendor":"siemens","product":"desigo pxc50-e.d"},{"vendor":"siemens","product":"desigo pxc64-u"},{"vendor":"siemens","product":"desigo pxm20-e"},{"vendor":"siemens","product":"desigo_pxc00-e.d_firmware"},{"vendor":"siemens","product":"desigo_pxc00-u_firmware"},{"vendor":"siemens","product":"desigo_pxc001-e.d_firmware"},{"vendor":"siemens","product":"desigo_pxc100-e.d_firmware"},{"vendor":"siemens","product":"desigo_pxc12-e.d_firmware"},{"vendor":"siemens","product":"desigo_pxc128-u_firmware"},{"vendor":"siemens","product":"desigo_pxc200-e.d_firmware"},{"vendor":"siemens","product":"desigo_pxc22-e.d_firmware"},{"vendor":"siemens","product":"desigo_pxc22.1-e.d_firmware"},{"vendor":"siemens","product":"desigo_pxc36.1-e.d_firmware"},{"vendor":"siemens","product":"desigo_pxc50-e.d_firmware"},{"vendor":"siemens","product":"desigo_pxc64-u_firmware"},{"vendor":"siemens","product":"desigo_pxm20-e_firmware"},{"vendor":"siemens","product":"nucleus net"},{"vendor":"siemens","product":"nucleus readystart v3"},{"vendor":"siemens","product":"nucleus source code"},{"vendor":"siemens","product":"nucleus_net"},{"vendor":"siemens","product":"nucleus_readystart_v3"},{"vendor":"siemens","product":"nucleus_source_code"},{"vendor":"siemens","product":"talon tc compact (bacnet)"},{"vendor":"siemens","product":"talon tc modular (bacnet)"},{"vendor":"siemens","product":"talon_tc_compact_firmware"},{"vendor":"siemens","product":"talon_tc_modular_firmware"}],"references":[{"url":"https://cert-portal.siemens.com/productcert/pdf/ssa-114589.pdf","tags":["x_refsource_MISC","x_transferred","Vendor Advisory"]},{"url":"https://cert-portal.siemens.com/productcert/pdf/ssa-044112.pdf","tags":["x_refsource_MISC","x_transferred","Vendor Advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2021-31887"},{"url":"https://github.com/advisories/GHSA-q5r7-v53q-5pgx"}],"sources":{"cve":[{"id":"CVE-2021-31887","description":"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 \u003c V3.5.4), APOGEE PXC Compact (P2 Ethernet) (All versions \u003c V2.8.19), APOGEE PXC Modular (BACnet) (All versions \u003c V3.5.4), APOGEE PXC Modular (P2 Ethernet) (All versions \u003c V2.8.19), Desigo PXC00-E.D (All versions \u003e= V2.3 and \u003c V6.30.016), Desigo PXC00-U (All versions \u003e= V2.3 and \u003c V6.30.016), Desigo PXC001-E.D (All versions \u003e= V2.3 and \u003c V6.30.016), Desigo PXC100-E.D (All versions \u003e= V2.3 and \u003c V6.30.016), Desigo PXC12-E.D (All versions \u003e= V2.3 and \u003c V6.30.016), Desigo PXC128-U (All versions \u003e= V2.3 and \u003c V6.30.016), Desigo PXC200-E.D (All versions \u003e= V2.3 and \u003c V6.30.016), Desigo PXC22-E.D (All versions \u003e= V2.3 and \u003c V6.30.016), Desigo PXC22.1-E.D (All versions \u003e= V2.3 and \u003c V6.30.016), Desigo PXC36.1-E.D (All versions \u003e= V2.3 and \u003c V6.30.016), Desigo PXC50-E.D (All versions \u003e= V2.3 and \u003c V6.30.016), Desigo PXC64-U (All versions \u003e= V2.3 and \u003c V6.30.016), Desigo PXM20-E (All versions \u003e= V2.3 and \u003c V6.30.016), Nucleus NET (All versions), Nucleus ReadyStart V3 (All versions \u003c V2017.02.4), Nucleus Source Code (All versions), TALON TC Compact (BACnet) (All versions \u003c V3.5.4), TALON TC Modular (BACnet) (All versions \u003c V3.5.4). 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. (FSMD-2021-0016)","status":"published","published":"2021-11-09T11:32:00Z","modified":"2024-08-03T23:10:30.65Z","cwes":["CWE-170"],"updated_at":"2026-11-02T14:33:05.665371Z"}],"euvd":[{"id":"EUVD-2021-18762","description":"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 \u003c V3.5.4), APOGEE PXC Compact (P2 Ethernet) (All versions \u003c V2.8.19), APOGEE PXC Modular (BACnet) (All versions \u003c V3.5.4), APOGEE PXC Modular (P2 Ethernet) (All versions \u003c V2.8.19), Desigo PXC00-E.D (All versions \u003e= V2.3 and \u003c V6.30.016), Desigo PXC00-U (All versions \u003e= V2.3 and \u003c V6.30.016), Desigo PXC001-E.D (All versions \u003e= V2.3 and \u003c V6.30.016), Desigo PXC100-E.D (All versions \u003e= V2.3 and \u003c V6.30.016), Desigo PXC12-E.D (All versions \u003e= V2.3 and \u003c V6.30.016), Desigo PXC128-U (All versions \u003e= V2.3 and \u003c V6.30.016), Desigo PXC200-E.D (All versions \u003e= V2.3 and \u003c V6.30.016), Desigo PXC22-E.D (All versions \u003e= V2.3 and \u003c V6.30.016), Desigo PXC22.1-E.D (All versions \u003e= V2.3 and \u003c V6.30.016), Desigo PXC36.1-E.D (All versions \u003e= V2.3 and \u003c V6.30.016), Desigo PXC50-E.D (All versions \u003e= V2.3 and \u003c V6.30.016), Desigo PXC64-U (All versions \u003e= V2.3 and \u003c V6.30.016), Desigo PXM20-E (All versions \u003e= V2.3 and \u003c V6.30.016), Nucleus NET (All versions), Nucleus ReadyStart V3 (All versions \u003c V2017.02.4), Nucleus Source Code (All versions), TALON TC Compact (BACnet) (All versions \u003c V3.5.4), TALON TC Modular (BACnet) (All versions \u003c V3.5.4). 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. (FSMD-2021-0016)","status":"published","published":"2021-11-09T11:32:00Z","modified":"2024-08-03T23:10:30Z","updated_at":"2026-11-03T03:24:37.97373Z"}],"ghsa":[{"id":"GHSA-q5r7-v53q-5pgx","title":"A vulnerability has been identified in APOGEE MBC (PPC) (BACnet) (All versions), APOGEE MBC (PPC)...","description":"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), APOGEE PXC Compact (P2 Ethernet) (All versions), APOGEE PXC Modular (BACnet) (All versions), APOGEE PXC Modular (P2 Ethernet) (All versions), Capital VSTAR (All versions), Nucleus NET (All versions), Nucleus ReadyStart V3 (All versions \u003c V2017.02.4), Nucleus Source Code (All versions), TALON TC Compact (BACnet) (All versions), TALON TC Modular (BACnet) (All versions). 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. (FSMD-2021-0016)","status":"published","published":"2022-05-24T22:28:53Z","modified":"2023-01-30T05:05:18Z","cvss":[{"version":"3.1","score":8.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","level":"high"}],"cwes":["CWE-170","CWE-787"],"updated_at":"2026-11-02T14:47:14.398767Z"}],"nvd":[{"id":"CVE-2021-31887","description":"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 \u003c V3.5.4), APOGEE PXC Compact (P2 Ethernet) (All versions \u003c V2.8.19), APOGEE PXC Modular (BACnet) (All versions \u003c V3.5.4), APOGEE PXC Modular (P2 Ethernet) (All versions \u003c V2.8.19), Desigo PXC00-E.D (All versions \u003e= V2.3 and \u003c V6.30.016), Desigo PXC00-U (All versions \u003e= V2.3 and \u003c V6.30.016), Desigo PXC001-E.D (All versions \u003e= V2.3 and \u003c V6.30.016), Desigo PXC100-E.D (All versions \u003e= V2.3 and \u003c V6.30.016), Desigo PXC12-E.D (All versions \u003e= V2.3 and \u003c V6.30.016), Desigo PXC128-U (All versions \u003e= V2.3 and \u003c V6.30.016), Desigo PXC200-E.D (All versions \u003e= V2.3 and \u003c V6.30.016), Desigo PXC22-E.D (All versions \u003e= V2.3 and \u003c V6.30.016), Desigo PXC22.1-E.D (All versions \u003e= V2.3 and \u003c V6.30.016), Desigo PXC36.1-E.D (All versions \u003e= V2.3 and \u003c V6.30.016), Desigo PXC50-E.D (All versions \u003e= V2.3 and \u003c V6.30.016), Desigo PXC64-U (All versions \u003e= V2.3 and \u003c V6.30.016), Desigo PXM20-E (All versions \u003e= V2.3 and \u003c V6.30.016), Nucleus NET (All versions), Nucleus ReadyStart V3 (All versions \u003c V2017.02.4), Nucleus Source Code (All versions), TALON TC Compact (BACnet) (All versions \u003c V3.5.4), TALON TC Modular (BACnet) (All versions \u003c V3.5.4). 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. (FSMD-2021-0016)","status":"published","published":"2021-11-09T12:15:09.587Z","modified":"2026-06-17T03:52:25.5Z","cvss":[{"version":"3.1","score":8.8,"vector":"CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:H/I:H/A:H","level":"high","assessor":"primary"},{"version":"2.0","score":6.5,"vector":"AV:N/AC:L/Au:S/C:P/I:P/A:P","level":"medium","assessor":"primary"}],"cwes":["CWE-170","CWE-787"],"updated_at":"2026-11-02T14:07:00.984108Z"}]}}