CVE-2020-3118

Cisco IOS XR Software Cisco Discovery Protocol Format String Vulnerability

HIGH

8.8

CVSS Score

Published: February 5, 2020 at 05:40 PM UTC

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

37 products affected across 1 vendorIOS XrAsr 9010Asr 9904

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Severity

HIGH8.8

Exploitation

CISA KEV

Exploit prediction

EPSS 12%

SSVC

Active

Actively Exploited

CISA Known Exploited Vulnerabilities (KEV) Catalog

EPSS Score11.7%

EPSS (Exploit Prediction Scoring System) estimates a 11.7% chance this CVE is exploited in the wild within the next 30 days — higher than 96% of all CVEs. It complements CVSS: a high EPSS on a mid-severity CVE can still be urgent.

Cisco IOS XR improperly validates string input from certain fields in Cisco Discovery Protocol messages. Exploitation could allow an unauthenticated, adjacent attacker to execute code with administrative privileges or cause a reload on an affected device.

Required Action

Apply updates per vendor instructions.

Ransomware Use

Unknown

Added to KEV

Nov 3, 2021

Remediation Due

May 3, 2022

1640 days overdue

Notes

https://nvd.nist.gov/vuln/detail/CVE-2020-3118

Description

A vulnerability in the Cisco Discovery Protocol implementation for Cisco IOS XR Software could allow an unauthenticated, adjacent attacker to execute arbitrary code or cause a reload on an affected device. The vulnerability is due to improper validation of string input from certain fields in 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 cause a stack overflow, which could allow the attacker to execute arbitrary code with administrative privileges on an affected device. 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.

IOS Xr · Cisco

95%

v < 6.6.36.6.0 ≤ v < 6.6.127.0.0 ≤ v < 7.0.25.2.5 6.4.2 6.5.3 6.6.25 7.0.1

Affected range stops below 6.6.12, so it looks safe — our inference, not a vendor statement

Affected range stops below 6.6.3, so it looks safe — our inference, not a vendor statement

Affected range stops below 7.0.2, so it looks safe — our inference, not a vendor statement

cisco-asr-9000 (environment) · cisco-asr-9000v (environment) · cisco-asr-9001 (environment) · cisco-asr-9006 (environment) · cisco-asr-9010 (environment) · cisco-asr-9901 (environment) · cisco-asr-9903 (environment) · cisco-asr-9904 (environment) · cisco-asr-9906 (environment) · cisco-asr-9910 (environment) · cisco-asr-9912 (environment) · cisco-asr-9920 (environment) · cisco-asr-9922 (environment) · cisco-crs-x (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-ncs-6008 (environment) · cisco-xrv-9000 (environment)

Asr 9000 · Ciscodevice

80%

All versions

Asr 9000V · Ciscodevice

80%

All versions

Asr 9001 · Ciscodevice

80%

All versions

Asr 9006 · Ciscodevice

80%

All versions