{"id":"CVE-2020-27738","aliases":["EUVD-2020-20242","GHSA-pqww-3mgv-r6mj"],"status":"published","title":"A vulnerability has been identified in Nucleus 4 (All versions \u003c V4.1.0), Nucleus NET (All...","description":"A vulnerability has been identified in APOGEE PXC Compact (BACnet) (All versions \u003c V3.5.5), APOGEE PXC Compact (P2 Ethernet) (All versions \u003c V2.8.20), APOGEE PXC Modular (BACnet) (All versions \u003c V3.5.5), APOGEE PXC Modular (P2 Ethernet) (All versions \u003c V2.8.20), Nucleus NET (All versions), Nucleus ReadyStart V3 (All versions \u003c V2017.02.3), Nucleus ReadyStart V4 (All versions \u003c V4.1.0), Nucleus Source Code (Versions including affected DNS modules), SIMOTICS CONNECT 400 (All versions \u003c V0.5.0.0), TALON TC Compact (BACnet) (All versions \u003c V3.5.5), TALON TC Modular (BACnet) (All versions \u003c V3.5.5). The DNS domain name record decompression functionality does not properly validate the pointer offset values. The parsing of malformed responses could result in a read access past the end of an allocated structure. An attacker with a privileged position in the network could leverage this vulnerability to cause a denial-of-service condition.","severity":{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:H/E:P/RL:O/RC:C","level":"medium","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-10","score":0.03659,"percentile":0.89718,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-119","CWE-788"],"published":"2021-04-22T20:42:20Z","modified":"2026-06-17T03:09:32Z","products":[{"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":"nucleus net"},{"vendor":"siemens","product":"nucleus readystart v3"},{"vendor":"siemens","product":"nucleus readystart v4"},{"vendor":"siemens","product":"nucleus source code"},{"vendor":"siemens","product":"nucleus_net"},{"vendor":"siemens","product":"nucleus_readystart_v3"},{"vendor":"siemens","product":"nucleus_readystart_v4"},{"vendor":"siemens","product":"nucleus_source_code"},{"vendor":"siemens","product":"simotics connect 400"},{"vendor":"siemens","product":"simotics_connect_400_firmware"},{"vendor":"siemens","product":"talon tc compact (bacnet)"},{"vendor":"siemens","product":"talon tc modular (bacnet)"}],"references":[{"url":"https://cert-portal.siemens.com/productcert/pdf/ssa-705111.pdf","tags":["x_transferred","Patch","Vendor Advisory"]},{"url":"https://cert-portal.siemens.com/productcert/pdf/ssa-669158.pdf","tags":["x_transferred","Patch","Vendor Advisory"]},{"url":"https://cert-portal.siemens.com/productcert/pdf/ssa-180579.pdf","tags":["x_transferred"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2020-27738"},{"url":"https://github.com/advisories/GHSA-pqww-3mgv-r6mj"}],"sources":{"cve":[{"id":"CVE-2020-27738","description":"A vulnerability has been identified in APOGEE PXC Compact (BACnet) (All versions \u003c V3.5.5), APOGEE PXC Compact (P2 Ethernet) (All versions \u003c V2.8.20), APOGEE PXC Modular (BACnet) (All versions \u003c V3.5.5), APOGEE PXC Modular (P2 Ethernet) (All versions \u003c V2.8.20), Nucleus NET (All versions), Nucleus ReadyStart V3 (All versions \u003c V2017.02.3), Nucleus ReadyStart V4 (All versions \u003c V4.1.0), Nucleus Source Code (Versions including affected DNS modules), SIMOTICS CONNECT 400 (All versions \u003c V0.5.0.0), TALON TC Compact (BACnet) (All versions \u003c V3.5.5), TALON TC Modular (BACnet) (All versions \u003c V3.5.5). The DNS domain name record decompression functionality does not properly validate the pointer offset values. The parsing of malformed responses could result in a read access past the end of an allocated structure. An attacker with a privileged position in the network could leverage this vulnerability to cause a denial-of-service condition.","status":"published","published":"2021-04-22T20:42:20Z","modified":"2024-08-04T16:18:45.774Z","cvss":[{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:H/E:P/RL:O/RC:C","level":"medium","assessor":"cna"}],"cwes":["CWE-788"],"updated_at":"2026-11-02T14:35:53.552996Z"}],"euvd":[{"id":"EUVD-2020-20242","description":"A vulnerability has been identified in APOGEE PXC Compact (BACnet) (All versions \u003c V3.5.5), APOGEE PXC Compact (P2 Ethernet) (All versions \u003c V2.8.20), APOGEE PXC Modular (BACnet) (All versions \u003c V3.5.5), APOGEE PXC Modular (P2 Ethernet) (All versions \u003c V2.8.20), Nucleus NET (All versions), Nucleus ReadyStart V3 (All versions \u003c V2017.02.3), Nucleus ReadyStart V4 (All versions \u003c V4.1.0), Nucleus Source Code (Versions including affected DNS modules), SIMOTICS CONNECT 400 (All versions \u003c V0.5.0.0), TALON TC Compact (BACnet) (All versions \u003c V3.5.5), TALON TC Modular (BACnet) (All versions \u003c V3.5.5). The DNS domain name record decompression functionality does not properly validate the pointer offset values. The parsing of malformed responses could result in a read access past the end of an allocated structure. An attacker with a privileged position in the network could leverage this vulnerability to cause a denial-of-service condition.","status":"published","published":"2021-04-22T20:42:20Z","modified":"2024-08-04T16:18:45Z","cvss":[{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:H/E:P/RL:O/RC:C","level":"medium"}],"updated_at":"2026-11-03T03:07:11.950168Z"}],"ghsa":[{"id":"GHSA-pqww-3mgv-r6mj","title":"A vulnerability has been identified in Nucleus 4 (All versions \u003c V4.1.0), Nucleus NET (All...","description":"A vulnerability has been identified in Nucleus 4 (All versions \u003c V4.1.0), Nucleus NET (All versions), Nucleus RTOS (versions including affected DNS modules), Nucleus ReadyStart (All versions \u003c V2017.02.3), Nucleus Source Code (versions including affected DNS modules), SIMOTICS CONNECT 400 (All versions \u003c V0.5.0.0), VSTAR (versions including affected DNS modules). The DNS domain name record decompression functionality does not properly validate the pointer offset values. The parsing of malformed responses could result in a read access past the end of an allocated structure. An attacker with a privileged position in the network could leverage this vulnerability to cause a denial-of-service condition.","status":"published","published":"2022-05-24T17:48:19Z","modified":"2023-08-17T05:02:14Z","cvss":[{"version":"3.1","score":7.4,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:H","level":"high"}],"cwes":["CWE-119","CWE-788"],"updated_at":"2026-11-02T14:54:45.82233Z"}],"nvd":[{"id":"CVE-2020-27738","description":"A vulnerability has been identified in APOGEE PXC Compact (BACnet) (All versions \u003c V3.5.5), APOGEE PXC Compact (P2 Ethernet) (All versions \u003c V2.8.20), APOGEE PXC Modular (BACnet) (All versions \u003c V3.5.5), APOGEE PXC Modular (P2 Ethernet) (All versions \u003c V2.8.20), Nucleus NET (All versions), Nucleus ReadyStart V3 (All versions \u003c V2017.02.3), Nucleus ReadyStart V4 (All versions \u003c V4.1.0), Nucleus Source Code (Versions including affected DNS modules), SIMOTICS CONNECT 400 (All versions \u003c V0.5.0.0), TALON TC Compact (BACnet) (All versions \u003c V3.5.5), TALON TC Modular (BACnet) (All versions \u003c V3.5.5). The DNS domain name record decompression functionality does not properly validate the pointer offset values. The parsing of malformed responses could result in a read access past the end of an allocated structure. An attacker with a privileged position in the network could leverage this vulnerability to cause a denial-of-service condition.","status":"published","published":"2021-04-22T21:15:09.313Z","modified":"2026-06-17T03:09:32.927Z","cvss":[{"version":"3.1","score":6.5,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:L/I:N/A:H","level":"medium","assessor":"secondary"},{"version":"3.1","score":7.4,"vector":"CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:H","level":"high","assessor":"primary"},{"version":"2.0","score":5.8,"vector":"AV:N/AC:M/Au:N/C:P/I:N/A:P","level":"medium","assessor":"primary"}],"cwes":["CWE-788","CWE-119"],"updated_at":"2026-11-02T14:06:39.25999Z"}]}}