CVE-2020-3566

Cisco IOS XR Software DVMRP Memory Exhaustion Vulnerability

HIGH

8.6

CVSS Score

Published: August 29, 2020 at 03:15 PM UTC

Updated: June 17, 2026 at 03:18 AM UTC

10 products affected across 1 vendorIOS XrAsr 9010Asr 9904

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Severity

HIGH8.6

Exploitation

CISA KEV

Exploit prediction

EPSS 4%

SSVC

Active

Actively Exploited

CISA Known Exploited Vulnerabilities (KEV) Catalog

EPSS Score3.7%

EPSS (Exploit Prediction Scoring System) estimates a 3.7% chance this CVE is exploited in the wild within the next 30 days — higher than 90% of all CVEs. It complements CVSS: a high EPSS on a mid-severity CVE can still be urgent.

Cisco IOS XR Distance Vector Multicast Routing Protocol (DVMRP) incorrectly handles Internet Group Management Protocol (IGMP) packets. Exploitation could allow an unauthenticated, remote attacker to immediately crash the IGMP process or make it consume available memory and eventually crash.

Required Action

Apply updates per vendor instructions.

Ransomware Use

Unknown

Added to KEV

Nov 3, 2021

Remediation Due

May 3, 2022

1641 days overdue

Notes

https://nvd.nist.gov/vuln/detail/CVE-2020-3566

Description

A vulnerability in the Distance Vector Multicast Routing Protocol (DVMRP) feature of Cisco IOS XR Software could allow an unauthenticated, remote attacker to exhaust process memory of an affected device. The vulnerability is due to insufficient queue management for Internet Group Management Protocol (IGMP) packets. An attacker could exploit this vulnerability by sending crafted IGMP traffic to an affected device. A successful exploit could allow the attacker to cause memory exhaustion, resulting in instability of other processes. These processes may include, but are not limited to, interior and exterior routing protocols. Cisco will release software updates that address this vulnerability.

Affected

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

IOS Xr · Cisco

95%

6.4.2

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)

Asr 9001 · Ciscodevice

80%

All versions

Asr 9006 · Ciscodevice

80%

All versions

Asr 9010 · Ciscodevice

80%

All versions

Asr 9901 · Ciscodevice

80%

All versions