CVE-2020-3566
Cisco IOS XR Software DVMRP Memory Exhaustion Vulnerability
Published Aug 29, 2020 · updated Jun 16, 2026 · cisco ios xr
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.
Timeline
Detection, updates, and resolution for this record.
Aug 29, 2020 · Catalog
Detected
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
Nov 3, 2021 · CISA KEV
Known exploited
Apply updates per vendor instructions.
May 3, 2022 · CISA KEV
Remediation due
Apply updates per vendor instructions.
Jun 16, 2026 · Catalog
Updated
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
Required action
Apply updates per vendor instructions.
CISA due date May 3, 2022
Affected
- cpe cisco/ios xr6.4.2
- vendor Cisco IOS XRversion unspecified
Sources
- CISA KEVCVE-2020-3566
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.
cisa.gov - CVE.orgCVE-2020-3566
Official CVE identifier
cve.org - FIRST EPSSCVE-2020-3566
30-day exploitation probability 3.7%
first.org - NIST NVDCVE-2020-3566
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
nvd.nist.gov