high
7.4
CWE
20
Advisory Published
Updated

CVE-2021-34714: Multiple Cisco Operating Systems Unidirectional Link Detection Denial of Service Vulnerability

First published: Thu Sep 23 2021(Updated: )

A vulnerability in the Unidirectional Link Detection (UDLD) feature of Cisco FXOS Software, Cisco IOS Software, Cisco IOS XE Software, Cisco IOS XR Software, and Cisco NX-OS Software could allow an unauthenticated, adjacent attacker to cause an affected device to reload. This vulnerability is due to improper input validation of the UDLD packets. An attacker could exploit this vulnerability by sending specifically crafted UDLD packets to an affected device. A successful exploit could allow the attacker to cause the affected device to reload, resulting in a denial of service (DoS) condition. Note: The UDLD feature is disabled by default, and the conditions to exploit this vulnerability are strict. An attacker must have full control of a directly connected device. On Cisco IOS XR devices, the impact is limited to the reload of the UDLD process.

Credit: ykramarz@cisco.com

Affected SoftwareAffected VersionHow to fix
Cisco FX-OS>=2.2<2.2.2.148
Cisco FX-OS>=2.3<2.3.1.216
Cisco FX-OS>=2.4<2.4.1.273
Cisco FX-OS>=2.6<2.6.1.224
Cisco FX-OS>=2.7<2.7.1.143
Cisco FX-OS>=2.8<2.8.1.143
Cisco FX-OS>=2.9<2.9.1.135
Cisco Firepower 4100 Series
Cisco Firepower 4110 Next-Generation Firewall
Cisco Firepower 4112 Firmware
Cisco Firepower 4115
Cisco Firepower 4120 Next-Generation Firewall
Cisco Firepower 4125 firmware
Cisco Firepower 4140 Next-Generation Firewall
Cisco Firepower 4145 firmware
Cisco Firepower 4150 Next-Generation Firewall
Cisco Firepower 9300 firmware
Cisco Firepower 9300
Cisco Firepower 9300
Cisco Firepower 9300
Cisco Firepower 9300
Cisco Firepower 9300
Cisco Firepower 9300
Cisco Firepower 9300
Cisco Firepower 9300 SM-56 X 3 firmware
Cisco Firepower 9300 SM-24
Cisco Firepower 9300 SM-36
Cisco Firepower 9300 SM-44
Cisco Firepower 9300
Cisco Firepower Extensible Operating System<=8.4\(3.115\)
Cisco IOS<=8.4\(3.115\)
Cisco IOS XE Web UI<=8.4\(3.115\)
Cisco IOS XRv 9000<=8.4\(3.115\)
Cisco NX-OS<=8.4\(3.115\)
Cisco MDS 9000 Series Multilayer Switches
Cisco MDS 9100
Cisco MDS 9132T
Cisco MDS 9134
Cisco MDS 9140
Cisco MDS 9148
Cisco MDS 9148S
Cisco MDS 9148T
Cisco MDS 9200
Cisco MDS 9216
Cisco MDS 9216
Cisco MDS 9216
Cisco MDS 9222i
Cisco MDS 9250i
Cisco MDS 9396S
Cisco MDS 9396T
Cisco MDS 9500
Cisco MDS 9500
Cisco MDS 9500
Cisco MDS 9513 Firmware
Cisco MDS 9700
Cisco MDS 9706 Firmware
Cisco MDS 9710 Firmware
Cisco MDS 9718 Firmware
Cisco Nexus 7000
Cisco Nexus 7000
Cisco Nexus 7000
Cisco Nexus 7000
Cisco Nexus 7000 9-Slot Firmware
Cisco Nexus 7000 Supervisor 1 Firmware
Cisco Nexus 7000 Supervisor 2E
Cisco Nexus 7000 Supervisor 2E Firmware
Cisco Nexus 7004 Firmware
Cisco Nexus 7009 Firmware
Cisco Nexus 7010 Firmware
Cisco Nexus 7018 Firmware
Cisco Nexus 7700 series
Cisco Nexus 7700 series
Cisco Nexus 7700 series
Cisco Nexus 7700 series
Cisco Nexus 7700 6-slot
Cisco Nexus 7700 Supervisor 2E Firmware
Cisco Nexus 7700 Supervisor 3E Firmware
Cisco Nexus 7702 firmware
Cisco Nexus 7706 firmware
Cisco Nexus 7710 Firmware
Cisco Nexus 7718 firmware
Cisco Firepower Extensible Operating System<=7.0\(3\)i7\(9\)
Cisco IOS<=7.0\(3\)i7\(9\)
Cisco IOS XE Web UI<=7.0\(3\)i7\(9\)
Cisco IOS XRv 9000<=7.0\(3\)i7\(9\)
Cisco NX-OS<=7.0\(3\)i7\(9\)
Cisco Nexus 3000
Cisco Nexus 3016Q Firmware
Cisco Nexus 3016Q Firmware
Cisco Nexus 3048 Firmware
Cisco Nexus 3064 Firmware
Cisco Nexus 3064
Cisco Nexus 3064
Cisco Nexus 3064x
Cisco Nexus 3064
Cisco Nexus 3064-X Firmware
Cisco Nexus 3100 Firmware
Cisco Nexus 3100V Firmware
Cisco Nexus 3100-Z firmware
Cisco Nexus 3100V Firmware
Cisco Nexus 31108PC-V Firmware
Cisco Nexus 31108PV-V Firmware
Cisco Nexus 31108TC-V Firmware
Cisco Nexus 31128PQ
Cisco Nexus 3132C-Z Firmware
Cisco Nexus 3132Q-XL
Cisco Nexus 3132Q-V Firmware
Cisco Nexus 3132Q-X/3132Q-XL
Cisco Nexus 3132Q-X/3132Q-XL
Cisco Nexus 3132Q-XL Firmware
Cisco Nexus 3164Q Firmware
Cisco Nexus 3172 Firmware
Cisco Nexus 3172PQ/PQ-XL
Cisco Nexus 3172PQ-XL Firmware
Cisco Nexus 3172PQ/PQ-XL
Cisco Nexus 3172TQ Firmware
Cisco Nexus 3172TQ-XL
Cisco Nexus 3172TQ-XL Firmware
Cisco Nexus 3200
Cisco Nexus 3232C
Cisco Nexus 3232C
Cisco Nexus 3264C-E Firmware
Cisco Nexus 3264Q Firmware
Cisco Nexus 3400 Firmware
Cisco Nexus 3408-S Firmware
Cisco Nexus 34180YC Firmware
Cisco Nexus 34200YC-SM Firmware
Cisco Nexus 3432D-S Firmware
Cisco Nexus 3464C Firmware
Cisco Nexus 3500 Platform
Cisco Nexus 3500 Platform Firmware
Cisco Nexus 3524-xl
Cisco Nexus 3524-xl
Cisco Nexus 3524-x/xl
Cisco Nexus 3524-XL Firmware
Cisco Nexus 3548-X/XL Firmware
Cisco Nexus 3548-X/XL
Cisco Nexus 3548-x/xl
Cisco Nexus 3548-X/XL
Cisco Nexus 3600 Firmware
Cisco Nexus 36180YC-R Firmware
Cisco Nexus 3636C-R Firmware
Cisco Nexus 9000 Firmware
Cisco Nexus 9000 in ACI mode
Cisco Nexus 9000
Cisco Nexus 9000 in standalone
Cisco NX-OS Nexus 9000 Series
Cisco Nexus 9200 firmware
Cisco Nexus 92160YC Switch
Cisco Nexus 9221C Firmware
Cisco Nexus 92300YC Firmware
Cisco Nexus 92304QC Switch
Cisco Nexus 92348GC-X Switch
Cisco Nexus 9236C Switch
Cisco Nexus 9272Q Switch
Cisco Nexus 9300 Firmware
Cisco Nexus
Cisco Nexus 93108TC-EX-24 Firmware
Cisco Nexus 93108TC-FX Switch
Cisco Nexus 93108TC-FX Switch
Cisco Nexus 93108TC-FX3P Firmware
Cisco Nexus 93120TX Firmware
Cisco Nexus 93128 Firmware
Cisco Nexus 93128 Firmware
Cisco Nexus 9316D-GX Firmware
Cisco Nexus 93180LC-EX Switch
Cisco Nexus 93180TC-EX Firmware
Cisco Nexus 93180YC-EX-24
Cisco Nexus 93180YC-EX-24 Firmware
Cisco Nexus 93180YC-FX Firmware
Cisco Nexus 93180YC-FX-24 Firmware
Cisco Nexus 93180YC-FX3 Firmware
Cisco Nexus 93180YC-FX3S Firmware
Cisco Nexus 93216TC-FX2 Firmware
Cisco Nexus 93240YC-FX2 Firmware
Cisco Nexus 9332C Firmware
Cisco Nexus 9332PQ Firmware
Cisco Nexus 93360YC-FX2
Cisco Nexus 9336C-FX2 Firmware
Cisco Nexus 9336C-FX2-E Firmware
Cisco Nexus N9336PQ
Cisco Nexus N9336PQ-X
Cisco Nexus 9348GC-FXP Firmware
Cisco Nexus 93600CD-GX Firmware
Cisco Nexus 9364c-h1
Cisco Nexus 9364C-GX Firmware
Cisco Nexus 9372PX-E
Cisco Nexus 9372PX-E Firmware
Cisco Nexus 9372TX
Cisco Nexus 9372TX-E Switch
Cisco Nexus 9396PX Firmware
Cisco Nexus 9396TX Firmware
Cisco Nexus 9500 Series
Cisco Nexus 9500 Supervisor A
Cisco Nexus 9500 Supervisor A+
Cisco Nexus 9500 Supervisor B firmware
Cisco Nexus 9500 Supervisor B+
Cisco Nexus 9500R Firmware
Cisco Nexus 9504 firmware
Cisco Nexus 9508
Cisco Nexus 9516 firmware
Cisco Firepower Extensible Operating System<=7.3\(8\)n1\(1\)
Cisco IOS<=7.3\(8\)n1\(1\)
Cisco IOS XE Web UI<=7.3\(8\)n1\(1\)
Cisco IOS XRv 9000<=7.3\(8\)n1\(1\)
Cisco NX-OS<=7.3\(8\)n1\(1\)
Cisco Nexus 5000 firmware
Cisco Nexus 5010
Cisco Nexus 5020
Cisco NX-OS for Nexus 5500 Platform Switches
Cisco Nexus 5548P Firmware
Cisco Nexus 5548UP Firmware
Cisco Nexus 5596T Firmware
Cisco Nexus 5596UP Firmware
Cisco Nexus 5600 Firmware
Cisco 56128p
Cisco Nexus 5624Q Firmware
Cisco Nexus 5648Q Firmware
Cisco Nexus 5672UP-16G
Cisco Nexus 5672UP-16G Firmware
Cisco Nexus 5696Q Firmware
Cisco Nexus 6000 firmware
Cisco Nexus 6001 Firmware
Cisco Nexus 6001P Firmware
Cisco Nexus 6001T Firmware
Cisco Nexus 6004 Firmware
Cisco Nexus 6004X Firmware
Cisco Firepower Extensible Operating System<=3.2\(3o\)a
Cisco IOS<=3.2\(3o\)a
Cisco IOS XE Web UI<=3.2\(3o\)a
Cisco IOS XRv 9000<=3.2\(3o\)a
Cisco NX-OS<=3.2\(3o\)a
Cisco UCS 6200 firmware
Cisco UCS 6248UP Fabric Interconnect
Cisco UCS 6248UP
Cisco UCS 6296UP Fabric Interconnect
Cisco UCS 6296UP
Cisco UCS 6300 firmware
Cisco UCS 6324 firmware
Cisco UCS 6324 Fabric Interconnect firmware
Cisco UCS 6332
Cisco UCS 6332-16UP
Cisco UCS 6332-16UP
Cisco UCS 6332 Fabric Interconnect firmware
Cisco Firepower Extensible Operating System<=4.1\(1a\)a
Cisco IOS<=4.1\(1a\)a
Cisco IOS XE Web UI<=4.1\(1a\)a
Cisco IOS XRv 9000<=4.1\(1a\)a
Cisco UCS 6400
Cisco UCS 6454 Fabric Interconnect

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Reference Links

Frequently Asked Questions

  • What is the severity of CVE-2021-34714?

    CVE-2021-34714 has been rated as high severity due to its potential to allow unauthorized access leading to device reloads.

  • How do I fix CVE-2021-34714?

    To fix CVE-2021-34714, upgrade to a patched version of the affected Cisco software as specified in the advisory.

  • Which Cisco products are affected by CVE-2021-34714?

    CVE-2021-34714 affects various versions of Cisco FXOS, IOS, IOS XE, IOS XR, and NX-OS software.

  • What types of attacks can exploit CVE-2021-34714?

    CVE-2021-34714 can be exploited by unauthenticated adjacent attackers to cause a denial of service by making the device reload.

  • Is there a workaround for CVE-2021-34714?

    Currently, no specific workarounds for CVE-2021-34714 have been documented; applying the latest software updates is the recommended action.

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