CVE:CVE-2021-27853
CNNVD:CNNVD-202209-2794
Cisco IOS等都是美国思科（Cisco）公司的产品。Cisco IOS是一套为其网络设备开发的操作系统。Cisco IOS XE Software是一个操作系统。Cisco Small Business是一个交换机。
Cisco IOS Software - Switches、Cisco IOS XE Software - Switches、Cisco IOS XE Software - Routers、Cisco IOS XR Software、Cisco Meraki - Switches、Cisco NX-OS Software、Cisco Small Business Switches存在安全漏洞，该漏洞源于使用 VLAN 0 标头和 LLC/SNAP 标头的组合可以绕过第 2 层网络过滤功能，例如 IPv6 RA 保护或 ARP 检查，攻击者利用该漏洞可以绕过受影响的思科产品上配置的第一跳安全 (FHS) 功能。
solution:Upgrade ieee ieee_802.2 to a higher version than 802.2h-1997,and avoid the version (,802.2h-1997]; Upgrade ietf p802.1q to a higher version than d1.0,and avoid the version (,d1.0]; Upgrade cisco catalyst_6503-e_firmware to a higher version than 15.5(01.01.85sy07,and avoid the version 15.5(01.01.85)sy07; Upgrade cisco catalyst_6504-e_firmware to a higher version than 15.5(01.01.85sy07,and avoid the version 15.5(01.01.85)sy07; Upgrade cisco catalyst_6506-e_firmware to a higher version than 15.5(01.01.85sy07,and avoid the version 15.5(01.01.85)sy07; Upgrade cisco catalyst_6509-e_firmware to a higher version than 15.5(01.01.85sy07,and avoid the version 15.5(01.01.85)sy07; Upgrade cisco catalyst_6509-neb-a_firmware to a higher version than 15.5(01.01.85sy07,and avoid the version 15.5(01.01.85)sy07; Upgrade cisco catalyst_6509-v-e_firmware to a higher version than 15.5(01.01.85sy07,and avoid the version 15.5(01.01.85)sy07; Upgrade cisco catalyst_6513-e_firmware to a higher version than 15.5(01.01.85sy07,and avoid the version 15.5(01.01.85)sy07; Upgrade cisco catalyst_6807-xl_firmware to a higher version than 15.5(01.01.85sy07,and avoid the version 15.5(01.01.85)sy07; Upgrade cisco catalyst_6840-x_firmware to a higher version than 15.5(01.01.85sy07,and avoid the version 15.5(01.01.85)sy07; Upgrade cisco catalyst_6880-x_firmware to a higher version than 15.5(01.01.85sy07,and avoid the version 15.5(01.01.85)sy07; Upgrade cisco catalyst_c6816-x-le_firmware to a higher version than 15.5(01.01.85sy07,and avoid the version 15.5(01.01.85)sy07; Upgrade cisco catalyst_c6824-x-le-40g_firmware to a higher version than 15.5(01.01.85sy07,and avoid the version 15.5(01.01.85)sy07; Upgrade cisco catalyst_c6832-x-le_firmware to a higher version than 15.5(01.01.85sy07,and avoid the version 15.5(01.01.85)sy07; Upgrade cisco catalyst_c6840-x-le-40g_firmware to a higher version than 15.5(01.01.85sy07,and avoid the version 15.5(01.01.85)sy07; Upgrade cisco catalyst_6800ia_firmware to a higher version than 15.5(01.01.85sy07,and avoid the version 15.5(01.01.85)sy07; Upgrade cisco ios_xe to a higher version than 17.3.3,15.2(07e02,15.2(07e03,17.4.1,17.6.1,and avoid the version 17.3.3,15.2(07)e02,15.2(07)e03,17.4.1,17.6.1; Upgrade cisco meraki_ms390_firmware to a higher version than -; Upgrade cisco meraki_ms210_firmware to a higher version than -; Upgrade cisco meraki_ms225_firmware to a higher version than -; Upgrade cisco meraki_ms250_firmware to a higher version than -; Upgrade cisco meraki_ms350_firmware to a higher version than -; Upgrade cisco meraki_ms355_firmware to a higher version than -; Upgrade cisco meraki_ms410_firmware to a higher version than -; Upgrade cisco meraki_ms420_firmware to a higher version than -; Upgrade cisco meraki_ms425_firmware to a higher version than -; Upgrade cisco meraki_ms450_firmware to a higher version than -; Upgrade cisco nexus_93180yc-ex_firmware to a higher version than 9.3(5,and avoid the version 9.3(5); Upgrade cisco nexus_93180yc-fx_firmware to a higher version than 9.3(5,and avoid the version 9.3(5); Upgrade cisco nexus_93180yc-fx3_firmware to a higher version than 9.3(5,and avoid the version 9.3(5); Upgrade cisco nexus_93240yc-fx2_firmware to a higher version than 9.3(5,and avoid the version 9.3(5); Upgrade cisco nexus_93360yc-fx2_firmware to a higher version than 9.3(5,and avoid the version 9.3(5); Upgrade cisco nexus_93120tx_firmware to a higher version than 9.3(5,and avoid the version 9.3(5); Upgrade cisco nexus_93108tc-ex_firmware to a higher version than 9.3(5,and avoid the version 9.3(5); Upgrade cisco nexus_9348gc-fxp_firmware to a higher version than 9.3(5,and avoid the version 9.3(5); Upgrade cisco nexus_93108tc-fx_firmware to a higher version than 9.3(5,and avoid the version 9.3(5); Upgrade cisco nexus_93108tc-fx3p_firmware to a higher version than 9.3(5,and avoid the version 9.3(5); Upgrade cisco nexus_93216tc-fx2_firmware to a higher version than 9.3(5,and avoid the version 9.3(5); Upgrade cisco n9k-c9316d-gx_firmware to a higher version than 9.3(5,and avoid the version 9.3(5); Upgrade cisco n9k-c93600cd-gx_firmware to a higher version than 9.3(5,and avoid the version 9.3(5); Upgrade cisco n9k-c9332d-gx2b_firmware to a higher version than 9.3(5,and avoid the version 9.3(5); Upgrade cisco n9k-c9348d-gx2a_firmware to a higher version than 9.3(5,and avoid the version 9.3(5); Upgrade cisco n9k-c9364d-gx2a_firmware to a higher version than 9.3(5,and avoid the version 9.3(5); Upgrade cisco n9k-x97160yc-ex_firmware to a higher version than 9.3(5,and avoid the version 9.3(5); Upgrade cisco n9k-x9788tc-fx_firmware to a higher version than 9.3(5,and avoid the version 9.3(5); Upgrade cisco n9k-x9564px_firmware to a higher version than 9.3(5,and avoid the version 9.3(5); Upgrade cisco n9k-x9464px_firmware to a higher version than 9.3(5,and avoid the version 9.3(5); Upgrade cisco n9k-x9564tx_firmware to a higher version than 9.3(5,and avoid the version 9.3(5); Upgrade cisco n9k-x9464tx2_firmware to a higher version than 9.3(5,and avoid the version 9.3(5); Upgrade cisco nexus_9636pq_firmware to a higher version than 9.3(5,and avoid the version 9.3(5); Upgrade cisco nexus_x9636q-r_firmware to a higher version than 9.3(5,and avoid the version 9.3(5); Upgrade cisco nexus_9536pq_firmware to a higher version than 9.3(5,and avoid the version 9.3(5); Upgrade cisco nexus_9432pq_firmware to a higher version than 9.3(5,and avoid the version 9.3(5); Upgrade cisco nexus_9736pq_firmware to a higher version than 9.3(5,and avoid the version 9.3(5); Upgrade cisco n9k-x9736c-fx_firmware to a higher version than 9.3(5,and avoid the version 9.3(5); Upgrade cisco n9k-x9732c-ex_firmware to a higher version than 9.3(5,and avoid the version 9.3(5); Upgrade cisco n9k-x9732c-fx_firmware to a higher version than 9.3(5,and avoid the version 9.3(5); Upgrade cisco n9k-x9736c-ex_firmware to a higher version than 9.3(5,and avoid the version 9.3(5); Upgrade cisco n9k-x9636c-rx_firmware to a higher version than 9.3(5,and avoid the version 9.3(5); Upgrade cisco n9k-x9636c-r_firmware to a higher version than 9.3(5,and avoid the version 9.3(5); Upgrade cisco n9k-x9432c-s_firmware to a higher version than 9.3(5,and avoid the version 9.3(5); Upgrade cisco nexus_9716d-gx_firmware to a higher version than 9.3(5,and avoid the version 9.3(5); Upgrade cisco nexus_9504_firmware to a higher version than 9.3(5,and avoid the version 9.3(5); Upgrade cisco nexus_9508_firmware to a higher version than 9.3(5,and avoid the version 9.3(5); Upgrade cisco nexus_9516_firmware to a higher version than 9.3(5,and avoid the version 9.3(5); Upgrade cisco nexus_92160yc-x_firmware to a higher version than 9.3(5,and avoid the version 9.3(5); Upgrade cisco nexus_9272q_firmware to a higher version than 9.3(5,and avoid the version 9.3(5); Upgrade cisco nexus_92304qc_firmware to a higher version than 9.3(5,and avoid the version 9.3(5); Upgrade cisco nexus_9236c_firmware to a higher version than 9.3(5,and avoid the version 9.3(5); Upgrade cisco nexus_92300yc_firmware to a higher version than 9.3(5,and avoid the version 9.3(5); Upgrade cisco nexus_92348gc-x_firmware to a higher version than 9.3(5,and avoid the version 9.3(5); Upgrade cisco nexus_9364c_firmware to a higher version than 9.3(5,and avoid the version 9.3(5); Upgrade cisco nexus_9336c-fx2_firmware to a higher version than 9.3(5,and avoid the version 9.3(5); Upgrade cisco nexus_9336c-fx2-e_firmware to a higher version than 9.3(5,and avoid the version 9.3(5); Upgrade cisco nexus_9332c_firmware to a higher version than 9.3(5,and avoid the version 9.3(5); Upgrade cisco nexus_9364c-gx_firmware to a higher version than 9.3(5,and avoid the version 9.3(5); Upgrade cisco nexus_9800_firmware to a higher version than 9.3(5,and avoid the version 9.3(5); Upgrade cisco sf500-24_firmware to a higher version than 3.0.0.61,and avoid the version 3.0.0.61; Upgrade cisco sf-500-24mp_firmware to a higher version than 3.0.0.61,and avoid the version 3.0.0.61; Upgrade cisco sf500-24p_firmware to a higher version than 3.0.0.61,and avoid the version 3.0.0.61; Upgrade cisco sf500-48_firmware to a higher version than 3.0.0.61,and avoid the version 3.0.0.61; Upgrade cisco sf500-48mp_firmware to a higher version than 3.0.0.61,and avoid the version 3.0.0.61; Upgrade cisco sf500-18p_firmware to a higher version than 3.0.0.61,and avoid the version 3.0.0.61; Upgrade cisco sg500-28_firmware to a higher version than 3.0.0.61,and avoid the version 3.0.0.61; Upgrade cisco sg500-28mpp_firmware to a higher version than 3.0.0.61,and avoid the version 3.0.0.61; Upgrade cisco sg500-28p_firmware to a higher version than 3.0.0.61,and avoid the version 3.0.0.61; Upgrade cisco sg500-52_firmware to a higher version than 3.0.0.61,and avoid the version 3.0.0.61; Upgrade cisco sg500-52mp_firmware to a higher version than 3.0.0.61,and avoid the version 3.0.0.61; Upgrade cisco sg500-52p_firmware to a higher version than 3.0.0.61,and avoid the version 3.0.0.61; Upgrade cisco sg500x-24_firmware to a higher version than 3.0.0.61,and avoid the version 3.0.0.61; Upgrade cisco sg500x-24mpp_firmware to a higher version than 3.0.0.61,and avoid the version 3.0.0.61; Upgrade cisco sg500x-24p_firmware to a higher version than 3.0.0.61,and avoid the version 3.0.0.61; Upgrade cisco sg500x-48_firmware to a higher version than 3.0.0.61,and avoid the version 3.0.0.61; Upgrade cisco sg500x-48mpp_firmware to a higher version than 3.0.0.61,and avoid the version 3.0.0.61; Upgrade cisco sg500x-48p_firmware to a higher version than 3.0.0.61,and avoid the version 3.0.0.61