CVE-2020-3566: Cisco IOS XR Software DVMRP Memory Exhaustion Vulnerability

Vulnerability summary

CVE-2020-3566 is a high (CVSS 8.6) Uncontrolled Resource Consumption vulnerability in Cisco IOS XR. It is known to be exploited: CISA lists it, first on 03-11-2021. EPSS estimates a 3.70% chance of exploitation in the next 30 days, higher than 89.6% of scored vulnerabilities.

Timeline

1. 29-08-2020
   PublishedVulnerability first disclosed.
2. 03-11-2021
   Added to CISA KEVCisco IOS XR Software DVMRP Memory Exhaustion Vulnerability
3. 03-05-2022
   CISA remediation dueApply updates per vendor instructions.
4. 21-10-2025
   Last modifiedVulnerability information updated.

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.

• CWE-400Uncontrolled Resource ConsumptionThe product does not properly control the allocation and maintenance of a limited resource.
• CWE-770Allocation of Resources Without Limits or ThrottlingThe product allocates a reusable resource or group of resources on behalf of an actor without imposing any intended restrictions on the size or number of resources that can be allocated.