{"id":"CVE-2021-21005","aliases":["EUVD-2021-8414","GHSA-jmcx-w32h-8qj4"],"status":"published","title":"Race Condition Vulnerability in Phoenix Contact FL SWITCH SMCS series products","description":"In Phoenix Contact FL SWITCH SMCS series products in multiple versions if an attacker sends a hand-crafted TCP-Packet with the Urgent-Flag set and the Urgent-Pointer set to 0, the network stack will crash. The device needs to be rebooted afterwards.","severity":{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-10","score":0.00678,"percentile":0.52654,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-362"],"published":"2021-06-25T18:25:53Z","modified":"2026-06-17T03:34:38Z","products":[{"vendor":"phoenix contact","product":"fl nat"},{"vendor":"phoenix contact","product":"fl switch"},{"vendor":"phoenixcontact","product":"fl_nat_smn_8tx-m_firmware"},{"vendor":"phoenixcontact","product":"fl_nat_smn_8tx_firmware"},{"vendor":"phoenixcontact","product":"fl_switch_smcs_14tx\\/2fx-sm_firmware"},{"vendor":"phoenixcontact","product":"fl_switch_smcs_14tx\\/2fx_firmware"},{"vendor":"phoenixcontact","product":"fl_switch_smcs_16tx_firmware"},{"vendor":"phoenixcontact","product":"fl_switch_smcs_4tx-pn_firmware"},{"vendor":"phoenixcontact","product":"fl_switch_smcs_6gt\\/2sfp_firmware"},{"vendor":"phoenixcontact","product":"fl_switch_smcs_6tx\\/2sfp_firmware"},{"vendor":"phoenixcontact","product":"fl_switch_smcs_8gt_firmware"},{"vendor":"phoenixcontact","product":"fl_switch_smcs_8tx-pn_firmware"},{"vendor":"phoenixcontact","product":"fl_switch_smcs_8tx_firmware"},{"vendor":"phoenixcontact","product":"fl_switch_smn_6tx\\/2fx_firmware"},{"vendor":"phoenixcontact","product":"fl_switch_smn_6tx\\/2fx_sm_firmware"},{"vendor":"phoenixcontact","product":"fl_switch_smn_6tx\\/2pof-pn_firmware"},{"vendor":"phoenixcontact","product":"fl_switch_smn_8tx-pn_firmware"}],"references":[{"url":"https://cert.vde.com/en-us/advisories/vde-2021-023","tags":["x_refsource_CONFIRM","x_transferred","Third Party Advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2021-21005"},{"url":"https://github.com/advisories/GHSA-jmcx-w32h-8qj4"}],"sources":{"cve":[{"id":"CVE-2021-21005","title":"Race Condition Vulnerability in Phoenix Contact FL SWITCH SMCS series products","description":"In Phoenix Contact FL SWITCH SMCS series products in multiple versions if an attacker sends a hand-crafted TCP-Packet with the Urgent-Flag set and the Urgent-Pointer set to 0, the network stack will crash. The device needs to be rebooted afterwards.","status":"published","published":"2021-06-25T18:25:53.099Z","modified":"2024-09-17T02:17:13.899Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high","assessor":"cna"}],"cwes":["CWE-362"],"updated_at":"2026-11-02T14:33:00.137099Z"}],"euvd":[{"id":"EUVD-2021-8414","description":"In Phoenix Contact FL SWITCH SMCS series products in multiple versions if an attacker sends a hand-crafted TCP-Packet with the Urgent-Flag set and the Urgent-Pointer set to 0, the network stack will crash. The device needs to be rebooted afterwards.","status":"published","published":"2021-06-25T18:25:53Z","modified":"2024-09-17T02:17:13Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high"}],"updated_at":"2026-11-03T00:28:41.388341Z"}],"ghsa":[{"id":"GHSA-jmcx-w32h-8qj4","title":"In Phoenix Contact FL SWITCH SMCS series products in multiple versions if an attacker sends a...","description":"In Phoenix Contact FL SWITCH SMCS series products in multiple versions if an attacker sends a hand-crafted TCP-Packet with the Urgent-Flag set and the Urgent-Pointer set to 0, the network stack will crash. The device needs to be rebooted afterwards.","status":"published","published":"2022-05-24T19:06:17Z","modified":"2023-01-30T05:00:31Z","cwes":["CWE-362"],"updated_at":"2026-11-02T14:46:13.539888Z"}],"nvd":[{"id":"CVE-2021-21005","description":"In Phoenix Contact FL SWITCH SMCS series products in multiple versions if an attacker sends a hand-crafted TCP-Packet with the Urgent-Flag set and the Urgent-Pointer set to 0, the network stack will crash. The device needs to be rebooted afterwards.","status":"published","published":"2021-06-25T19:15:08.797Z","modified":"2026-06-17T03:34:38.773Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high","assessor":"secondary"},{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high","assessor":"primary"},{"version":"2.0","score":7.8,"vector":"AV:N/AC:L/Au:N/C:N/I:N/A:C","level":"high","assessor":"primary"}],"cwes":["CWE-362"],"updated_at":"2026-11-02T14:06:54.892562Z"}]}}