CVE:CVE-2021-21003
CNNVD:CNNVD-202106-1742
Phoenix Contact FL SWITCH是德国菲尼克斯电气（Phoenix Contact）公司的一款工业级以太网交换机。TCP（Transmission Control Protocol,传输控制协议）是一种面向连接的、可靠的、基于字节流的传输层通信协议，由IETF的RFC 793定义。
Phoenix Contact FL COMSERVER UNI 存在安全漏洞，该漏洞源于在Phoenix Contact FL SWITCH SMCS系列产品中，多个版本的tcp - packet碎片可能会导致Web-、SNMP-和ICMP-Echo服务的拒绝服务。
solution:Upgrade phoenixcontact fl_switch_smcs_16tx_firmware to a higher version than 4.70,and avoid the version (,4.70]; Upgrade phoenixcontact fl_switch_smcs_14tx/2fx_firmware to a higher version than 4.70,and avoid the version (,4.70]; Upgrade phoenixcontact fl_switch_smcs_14tx/2fx-sm_firmware to a higher version than 4.70,and avoid the version (,4.70]; Upgrade phoenixcontact fl_switch_smcs_8gt_firmware to a higher version than 4.70,and avoid the version (,4.70]; Upgrade phoenixcontact fl_switch_smcs_6gt/2sfp_firmware to a higher version than 4.70,and avoid the version (,4.70]; Upgrade phoenixcontact fl_switch_smcs_8tx-pn_firmware to a higher version than 4.70,and avoid the version (,4.70]; Upgrade phoenixcontact fl_switch_smcs_4tx-pn_firmware to a higher version than 4.70,and avoid the version (,4.70]; Upgrade phoenixcontact fl_switch_smcs_8tx_firmware to a higher version than 4.70,and avoid the version (,4.70]; Upgrade phoenixcontact fl_switch_smcs_6tx/2sfp_firmware to a higher version than 4.70,and avoid the version (,4.70]; Upgrade phoenixcontact fl_switch_smn_6tx/2pof-pn_firmware to a higher version than 4.70,and avoid the version (,4.70]; Upgrade phoenixcontact fl_switch_smn_8tx-pn_firmware to a higher version than 4.70,and avoid the version (,4.70]; Upgrade phoenixcontact fl_switch_smn_6tx/2fx_firmware to a higher version than 4.70,and avoid the version (,4.70]; Upgrade phoenixcontact fl_switch_smn_6tx/2fx_sm_firmware to a higher version than 4.70,and avoid the version (,4.70]; Upgrade phoenixcontact fl_nat_smn_8tx_firmware to a higher version than 4.63,and avoid the version (,4.63]; Upgrade phoenixcontact fl_nat_smn_8tx-m_firmware to a higher version than 4.63,and avoid the version (,4.63]