CVE-2020-3566
Cisco IOS XR Software DVMRP Memory Exhaustion Vulnerability
Cisco · IOS XR
Vulnerability details
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.
Added to CISA KEV: 2021-11-03
Ransomware campaign use: Unknown
CISA due date: 2022-05-03
Defensive guidance from CISA
Apply updates per vendor instructions.
This is the source's required-action field, not an independently validated patch procedure. Refer to the vendor for exact affected versions and fixes.
Source catalog date: 2026-11-06T19:44:45.1797Z · Last retrieved: 2026-11-06 21:02:26 UTC