CVE-2020-3120

Cisco FXOS, IOS XR, and NX-OS Software Cisco Discovery Protocol Denial of Service Vulnerability

MEDIUM

6.5

CVSS Score

Published: February 5, 2020 at 05:50 PM UTC

Updated: June 17, 2026 at 03:17 AM UTC

144 products affected across 1 vendorNx OSIOS XrFirepower Extensible Operating System

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Severity

MEDIUM6.5

Exploit prediction

EPSS 2%

SSVC

No known exploit

Description

A vulnerability in the Cisco Discovery Protocol implementation for Cisco FXOS Software, Cisco IOS XR Software, and Cisco NX-OS Software could allow an unauthenticated, adjacent attacker to cause a reload of an affected device, resulting in a denial of service (DoS) condition. The vulnerability is due to a missing check when the affected software processes Cisco Discovery Protocol messages. An attacker could exploit this vulnerability by sending a malicious Cisco Discovery Protocol packet to an affected device. A successful exploit could allow the attacker to exhaust system memory, causing the device to reload. Cisco Discovery Protocol is a Layer 2 protocol. To exploit this vulnerability, an attacker must be in the same broadcast domain as the affected device (Layer 2 adjacent).

Affected

Our own answer: ranges merged, affected separated from platform-only, with confidence and review flags.

Firepower Extensible Operating System · Cisco

95%

v ≤ 2.3.1.1732.6 ≤ v < 2.6.1.1872.7 ≤ v < 2.7.1.106

Affected range stops below 2.6.1.187, so it looks safe — our inference, not a vendor statement

Affected range stops below 2.7.1.106, so it looks safe — our inference, not a vendor statement

cisco-firepower-4110 (environment) · cisco-firepower-4115 (environment) · cisco-firepower-4120 (environment) · cisco-firepower-4125 (environment) · cisco-firepower-4140 (environment) · cisco-firepower-4145 (environment) · cisco-firepower-4150 (environment) · cisco-firepower-9300 (environment)

Fxos · Cisco

95%

2.4

IOS Xr · Cisco

95%

v < 2.3.1.1735.2.5 6.4.2 6.5.3 6.6.25 7.0.1

Affected range stops below 2.3.1.173, so it looks safe — our inference, not a vendor statement

cisco-asr-9000v (environment) · cisco-asr-9001 (environment) · cisco-asr-9006 (environment) · cisco-asr-9010 (environment) · cisco-asr-9901 (environment) · cisco-asr-9904 (environment) · cisco-asr-9906 (environment) · cisco-asr-9910 (environment) · cisco-asr-9912 (environment) · cisco-asr-9922 (environment) · cisco-crs (environment) · cisco-ncs-5001 (environment) · cisco-ncs-5002 (environment) · cisco-ncs-5011 (environment) · cisco-ncs-540-12z20g-sys-a (environment) · cisco-ncs-540-12z20g-sys-d (environment) · cisco-ncs-540-24z8q2c-sys (environment) · cisco-ncs-540-28z4c-sys-a (environment) · cisco-ncs-540-28z4c-sys-d (environment) · cisco-ncs-540-acc-sys (environment) · cisco-ncs-540l (environment) · cisco-ncs-540x-12z16g-sys-a (environment) · cisco-ncs-540x-12z16g-sys-d (environment) · cisco-ncs-540x-16z4g8q2c-a (environment) · cisco-ncs-540x-16z4g8q2c-d (environment) · cisco-ncs-540x-acc-sys (environment) · cisco-ncs-5501 (environment) · cisco-ncs-5501-se (environment) · cisco-ncs-5502 (environment) · cisco-ncs-5502-se (environment) · cisco-ncs-5508 (environment) · cisco-ncs-5516 (environment) · cisco-ncs-560 (environment) · cisco-ncs-6000 (environment) · cisco-xrv-9000 (environment)

Nx OS · Cisconpm

95%

v ≤ 5.2v < 13.2(9b)v < 5.2(1)sv3(4.1b)v < 6.2(24)v < 7.3(6)n1(1)14.0 ≤ v < 14.2(1j)5.2 ≤ v < 5.2(1)sv5(1.3)5.2 ≤ v < 6.2(29)7.0(3)f2 ≤ v < 9.3(2)7.0(3)i ≤ v < 7.0(3)i7(8)7.2 ≤ v < 7.3(5)d1(1)7.3 ≤ v < 8.4(1a)8.0 ≤ v < 8.2(5)8.3 ≤ v < 8.4(2)

Affected range stops below 13.2(9b), so it looks safe — our inference, not a vendor statement

Affected range stops below 14.2(1j), so it looks safe — our inference, not a vendor statement

Affected range stops below 5.2(1)sv3(4.1b), so it looks safe — our inference, not a vendor statement

Affected range stops below 5.2(1)sv5(1.3), so it looks safe — our inference, not a vendor statement

Affected range stops below 6.2(24), so it looks safe — our inference, not a vendor statement

Affected range stops below 6.2(29), so it looks safe — our inference, not a vendor statement

Affected range stops below 7.0(3)i7(8), so it looks safe — our inference, not a vendor statement

Affected range stops below 7.3(5)d1(1), so it looks safe — our inference, not a vendor statement

Affected range stops below 7.3(6)n1(1), so it looks safe — our inference, not a vendor statement

Affected range stops below 8.2(5), so it looks safe — our inference, not a vendor statement

Affected range stops below 8.4(1a), so it looks safe — our inference, not a vendor statement

Affected range stops below 8.4(2), so it looks safe — our inference, not a vendor statement

Affected range stops below 9.3(2), so it looks safe — our inference, not a vendor statement

cisco-mds-9132t (environment) · cisco-mds-9148s (environment) · cisco-mds-9148t (environment) · cisco-mds-9216 (environment) · cisco-mds-9216a (environment) · cisco-mds-9216i (environment) · cisco-mds-9222i (environment) · cisco-mds-9506 (environment) · cisco-mds-9509 (environment) · cisco-mds-9513 (environment) · cisco-mds-9706 (environment) · cisco-mds-9710 (environment) · cisco-mds-9718 (environment) · cisco-nexus-1000v (environment) · cisco-nexus-1000ve (environment) · cisco-nexus-3016 (environment) · cisco-nexus-3048 (environment) · cisco-nexus-3064 (environment) · cisco-nexus-3064-t (environment) · cisco-nexus-31108pc-v (environment) · cisco-nexus-31108tc-v (environment) · cisco-nexus-31128pq (environment) · cisco-nexus-3132c-z (environment) · cisco-nexus-3132q (environment) · cisco-nexus-3132q-v (environment) · cisco-nexus-3132q-xl (environment) · cisco-nexus-3164q (environment) · cisco-nexus-3172 (environment) · cisco-nexus-3172pq-xl (environment) · cisco-nexus-3172tq (environment) · cisco-nexus-3172tq-32t (environment) · cisco-nexus-3172tq-xl (environment) · cisco-nexus-3232c (environment) · cisco-nexus-3264c-e (environment) · cisco-nexus-3264q (environment) · cisco-nexus-3408-s (environment) · cisco-nexus-34180yc (environment) · cisco-nexus-3432d-s (environment) · cisco-nexus-3464c (environment) · cisco-nexus-3524 (environment) · cisco-nexus-3524-x (environment) · cisco-nexus-3524-xl (environment) · cisco-nexus-3548 (environment) · cisco-nexus-3548-x (environment) · cisco-nexus-3548-xl (environment) · cisco-nexus-36180yc-r (environment) · cisco-nexus-3636c-r (environment) · cisco-nexus-5548p (environment) · cisco-nexus-5548up (environment) · cisco-nexus-5596t (environment) · cisco-nexus-5596up (environment) · cisco-nexus-56128p (environment) · cisco-nexus-5624q (environment) · cisco-nexus-5648q (environment) · cisco-nexus-5672up (environment) · cisco-nexus-5696q (environment) · cisco-nexus-7000 (environment) · cisco-nexus-7700 (environment) · cisco-nexus-9000v (environment) · cisco-nexus-92160yc-x (environment) · cisco-nexus-92300yc (environment) · cisco-nexus-92304qc (environment) · cisco-nexus-92348gc-x (environment) · cisco-nexus-9236c (environment) · cisco-nexus-9272q (environment) · cisco-nexus-93108tc-ex (environment) · cisco-nexus-93108tc-fx (environment) · cisco-nexus-93120tx (environment) · cisco-nexus-93128tx (environment) · cisco-nexus-93180lc-ex (environment) · cisco-nexus-93180yc-ex (environment) · cisco-nexus-93180yc-fx (environment) · cisco-nexus-93216tc-fx2 (environment) · cisco-nexus-93240yc-fx2 (environment) · cisco-nexus-9332c (environment) · cisco-nexus-9332pq (environment) · cisco-nexus-93360yc-fx2 (environment) · cisco-nexus-9336c-fx2 (environment) · cisco-nexus-9336pq-aci-spine (environment) · cisco-nexus-9348gc-fxp (environment) · cisco-nexus-9364c (environment) · cisco-nexus-9372px (environment) · cisco-nexus-9372px-e (environment) · cisco-nexus-9372tx (environment) · cisco-nexus-9372tx-e (environment) · cisco-nexus-9396px (environment) · cisco-nexus-9396tx (environment) · cisco-nexus-9504 (environment) · cisco-nexus-9508 (environment) · cisco-nexus-9516 (environment)

Ucs Manager · Cisco

95%

v < 3.2(3m)4.0 ≤ v < 4.0(4g)

Affected range stops below 3.2(3m), so it looks safe — our inference, not a vendor statement

Affected range stops below 4.0(4g), so it looks safe — our inference, not a vendor statement

cisco-ucs-6248up (environment) · cisco-ucs-6296up (environment) · cisco-ucs-6300 (environment) · cisco-ucs-6324 (environment) · cisco-ucs-64108 (environment) · cisco-ucs-6454 (environment)

Asr 9000V · Ciscodevice

80%

All versions

Asr 9001 · Ciscodevice

80%

All versions

Asr 9006 · Ciscodevice

80%

All versions

Asr 9010 · Ciscodevice

80%

All versions