CVE-2021-21005

HIGH

Phoenix Contact FL SWITCH SMCS - DoS

Title source: llm
STIX 2.1

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.

References (1)

Core 1
Core References
Third Party Advisory x_refsource_confirm
https://cert.vde.com/en-us/advisories/vde-2021-023

Scores

CVSS v3 7.5
EPSS 0.0068
EPSS Percentile 47.5%
Attack Vector NETWORK
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Details

CWE
CWE-362
Status published
Products (15)
phoenixcontact/fl_nat_smn_8tx-m_firmware < 4.63
phoenixcontact/fl_nat_smn_8tx_firmware < 4.63
phoenixcontact/fl_switch_smcs_14tx\/2fx-sm_firmware < 4.70
phoenixcontact/fl_switch_smcs_14tx\/2fx_firmware < 4.70
phoenixcontact/fl_switch_smcs_16tx_firmware < 4.70
phoenixcontact/fl_switch_smcs_4tx-pn_firmware < 4.70
phoenixcontact/fl_switch_smcs_6gt\/2sfp_firmware < 4.70
phoenixcontact/fl_switch_smcs_6tx\/2sfp_firmware < 4.70
phoenixcontact/fl_switch_smcs_8gt_firmware < 4.70
phoenixcontact/fl_switch_smcs_8tx-pn_firmware < 4.70
... and 5 more
Published Jun 25, 2021
Tracked Since Feb 18, 2026