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

> CVE-2020-3566: Cisco IOS XR Software DVMRP Memory Exhaustion Vulnerability. CVSS 8.6 (CVSS 3.1), in CISA KEV.

Canonical: https://rewindex.com/cve/CVE-2020-3566
Last updated: 2025-10-21T23:35:37Z

- Published: 2020-08-29 15:15 UTC · Updated: 2025-10-21 23:35 UTC · Assigner: cisco
- CVSS: 8.6 (CVSS 3.1) · Severity: High · Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
- EPSS: 3.7%, 90th percentile (scored 2026-10-25)
- CISA KEV: yes, added 2021-11-03, federal due date 2022-05-03, ransomware use: Unknown
- CWE: CWE-400

## 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.

## CISA required action

Apply updates per vendor instructions.

## Affected vendors and products

- Cisco: Cisco IOS XR Software

## References

- [CVE record on cve.org](https://www.cve.org/CVERecord?id=CVE-2020-3566)
- [NVD entry](https://nvd.nist.gov/vuln/detail/CVE-2020-3566)
- [https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-iosxr-dvmrp-memexh-dSmpdvfz](https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-iosxr-dvmrp-memexh-dSmpdvfz)

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_Sources: CVE records from the CVE Program (cve.org). CVE® is a registered trademark of The MITRE Corporation. (https://www.cve.org/) This product uses data from the NVD API but is not endorsed or certified by the NVD. (https://nvd.nist.gov/) Known Exploited Vulnerabilities catalog from CISA. (https://www.cisa.gov/known-exploited-vulnerabilities-catalog) EPSS scores from FIRST (Exploit Prediction Scoring System). (https://www.first.org/epss/)_


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Canonical: https://rewindex.com/cve/CVE-2020-3566 · Markdown: https://rewindex.com/cve/CVE-2020-3566.md · JSON: https://rewindex.com/api/v1/cves/CVE-2020-3566 · Data licensed CC BY 4.0 (https://creativecommons.org/licenses/by/4.0/) · Generated 2026-10-26T02:13:39.300Z