November 3, 2021 · Applied Cybernetics Group
CVE-2020-3566 — Cisco IOS XR
Cisco IOS XR Software DVMRP Memory Exhaustion Vulnerability
- Added to KEV
2021-11-03- Federal due date
2022-05-03- Vendor
- Cisco
- Product
- IOS XR
- EPSS
- 84.5th percentile (score 0.021, as of
2026-06-08) - NVD CVSS v3.1
- —
- Ransomware use
- Unknown
- Upstream
- https://nvd.nist.gov/vuln/detail/CVE-2020-3566
CISA short 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.
Required action
Apply updates per vendor instructions.