Is CVE-2020-3566 actively exploited?

Yes. CVE-2020-3566 is listed in the CISA Known Exploited Vulnerabilities (KEV) catalog, which means exploitation in the wild has been confirmed.

Can CVE-2020-3566 be exploited remotely?

The attack vector of CVE-2020-3566 has not been classified yet.

What is the CVSS score of CVE-2020-3566?

CVE-2020-3566 has not received a CVSS score yet.

HOME VULNERABILITIESCVE-2020-3566

HIGHCISA KEVIN THE WILD

CVE-2020-3566

Published: November 3, 2021

EPSS:5.05%probability of exploitation in 30 daysPercentile:89.6th

Official Description

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.

NVD Source

CISA KEV Advisory

Cisco IOS XR Software DVMRP Memory Exhaustion Vulnerability

Added to KEV: 2021-11-03Federal patch deadline: 2022-05-03

Required Action (CISA)

Apply updates per vendor instructions.

Risk Analysis

This Cisco IOS XR vulnerability in the DVMRP module incorrectly handles IGMP packets, allowing an unauthenticated, remote attacker to crash the IGMP process or consume all memory, leading to a system crash. Its inclusion in the KEV catalog confirms active exploitation, making it a critical denial-of-service risk.

This vulnerability is actively being exploited in the wild. The flaw is remotely exploitable and does not require authentication.

Recommended Action

Administrators should apply the latest security updates for Cisco IOS XR to address this denial-of-service vulnerability.

Generated by the CTIWATCH analysis pipeline from this CVE's metadata (CVSS, EPSS, KEV status, exploit intelligence). Verify against vendor advisories before acting.

Technical Analysis

CVE-2020-3566 requires local access, meaning attackers must already have a foothold on the target system.

Exploitation requires some privileges, which limits the exposure to scenarios where an attacker has already gained initial access.

CISA has added CVE-2020-3566 to the Known Exploited Vulnerabilities (KEV) catalog, confirming active exploitation in the wild. U.S. federal agencies are required to patch this within the mandated timeframe, and all organizations should treat remediation as urgent.