CVE:CVE-2021-34714
CNNVD:CNNVD-202109-1581
Cisco NX-OS Software等都是美国思科（Cisco）公司的产品。Cisco NX-OS Software是一套交换机使用的数据中心级操作系统软件。Cisco IOS是一套为其网络设备开发的操作系统。IOS XE是一套为其网络设备开发的操作系统。
Cisco FXOS 软件、Cisco IOS 软件、Cisco IOS XE 软件、Cisco IOS XR 软件和 Cisco NX-OS 软件存在输入验证错误漏洞，该漏洞源于软件的单向链路检测(UDLD)功能对UDLD报文的输入验证不正确。漏洞可能允许未经认证的相邻攻击者利用漏洞导致受影响设备重新加载。攻击者可以通过向受影响的设备发送专门设计的UDLD包来利用这个漏洞。成功的攻击可以让攻击者通过漏洞使受影响的设备重新加载，从而导致拒绝服务(DoS)攻击。
solution:Upgrade cisco fxos to a higher version than 2.2.2.148,2.3.1.216,2.4.1.273,2.6.1.224,2.7.1.143,2.8.1.143,2.9.1.135,and avoid the version [2.2,2.2.2.148),[2.3,2.3.1.216),[2.4,2.4.1.273),[2.6,2.6.1.224),[2.7,2.7.1.143),[2.8,2.8.1.143),[2.9,2.9.1.135); Upgrade cisco firepower_extensible_operating_system to a higher version than 8.4\(3.115\,7.0\(3\i7\(9\,7.3\(8\n1\(1\,3.2\(3o\a,4.1\(1a\a,and avoid the version (,8.4\(3.115\)],(,7.0\(3\)i7\(9\)],(,7.3\(8\)n1\(1\)],(,3.2\(3o\)a],(,4.1\(1a\)a]; Upgrade cisco ios to a higher version than 8.4\(3.115\,7.0\(3\i7\(9\,7.3\(8\n1\(1\,3.2\(3o\a,4.1\(1a\a,and avoid the version (,8.4\(3.115\)],(,7.0\(3\)i7\(9\)],(,7.3\(8\)n1\(1\)],(,3.2\(3o\)a],(,4.1\(1a\)a]; Upgrade cisco ios_xe to a higher version than 8.4\(3.115\,7.0\(3\i7\(9\,7.3\(8\n1\(1\,3.2\(3o\a,4.1\(1a\a,and avoid the version (,8.4\(3.115\)],(,7.0\(3\)i7\(9\)],(,7.3\(8\)n1\(1\)],(,3.2\(3o\)a],(,4.1\(1a\)a]; Upgrade cisco ios_xr to a higher version than 8.4\(3.115\,7.0\(3\i7\(9\,7.3\(8\n1\(1\,3.2\(3o\a,4.1\(1a\a,and avoid the version (,8.4\(3.115\)],(,7.0\(3\)i7\(9\)],(,7.3\(8\)n1\(1\)],(,3.2\(3o\)a],(,4.1\(1a\)a]; Upgrade cisco nx-os to a higher version than 8.4\(3.115\,7.0\(3\i7\(9\,7.3\(8\n1\(1\,3.2\(3o\a,and avoid the version (,8.4\(3.115\)],(,7.0\(3\)i7\(9\)],(,7.3\(8\)n1\(1\)],(,3.2\(3o\)a]