Input validation error in Cisco Systems, Inc products - CVE-2021-34714

Vulnerability identifier: #VU56875

CSH Severity: Medium

CVSS v4: 7.1 [CVSS:4.0/AV:A/AC:L/AT:N/PR:N/UI:N/VC:N/VI:N/VA:H/SC:N/SI:N/SA:N]

CVE-ID: CVE-2021-34714

CWE-ID: CWE-20

Exploitation vector: Adjecent network

Exploit availability: No public exploit available

The vulnerability allows a remote attacker to perform a denial of service (DoS) attack.

The vulnerability exists due to insufficient validation of user-supplied input in the Unidirectional Link Detection (UDLD) feature. A remote attacker on the local network can pass specially crafted input to the application and perform a denial of service (DoS) attack.

UCS 6400 Series Fabric Interconnects
UCS 6300 Series Fabric Interconnects
UCS 6200 Series Fabric Interconnects
Cisco Nexus 9000 Series Switches NX-OS Mode
Cisco Nexus 7000 Series Switches
Cisco Nexus 6000 Series Switches
Nexus 5600 Platform Switches
Nexus 5500 Platform Switches
Cisco Nexus 3000 Series Switches
Cisco MDS 9000 Series Multilayer Switches
Cisco Firepower 9300 Security Appliance
Cisco Firepower 4100 Series Next-Generation Firewall
Cisco FXOS
Cisco IOS XR
Cisco NX-OS
Cisco IOS XE
Cisco IOS
Cisco UCS Manager

Install updates from vendor's website.

Cisco FXOS - addressed in versions 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
Cisco UCS Manager - addressed in versions 4.0(4l), 4.1(2c)
Cisco IOS XR - addressed in versions 6.7.4, 6.8.1, 7.2.2, 7.3.1, 7.3.15, 7.4.1
Cisco NX-OS - addressed in versions 4.1(3a)UCSM, 7.0(3)I7(10), 9.3(5.116), 9.3(5.123)
Cisco IOS XE - addressed in versions 16.9.8, 16.12.5, 16.12.5 b, 16.12.6, 17.3.3, 17.3.4, 17.5.1, 17.6.1
Cisco IOS - addressed in versions 16.9.8, 16.12.5, 16.12.5 b, 16.12.6, 17.3.3, 17.3.4, 17.5.1, 17.6.1

• https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ios-nxos-xr-udld-dos-W5hGHgtQ

• Denial of service in multiple Cisco Operating Systems