# CVE-2020-3569: Cisco IOS XR Software DVMRP Memory Exhaustion Vulnerability

Source: https://junglewise.ai/threats/cve-2020-3569-cisco-ios-xr-software-dvmrp-memory-exhaustion-vulnerability  
Publisher: Junglewise Threat Intelligence, https://junglewise.ai/threats  
Published: 2021-11-03. Updated: 2026-05-10  
License: CC BY 4.0 with a link back

CVE-2020-3569 · Severity: critical · CVSS 8.6 · Exploited in the wild · Published 2021-11-03

A vulnerability in the Distance Vector Multicast Routing Protocol (DVMRP) feature of Cisco IOS XR Software allows unauthenticated remote attackers to cause a denial of service. By sending crafted IGMP packets, an attacker can crash the IGMP process or exhaust system memory, potentially destabilizing other routing protocols.

Technologies: [Cisco IOS XR](https://junglewise.ai/threats/technologies/ios-xr). Vendors: [Cisco](https://junglewise.ai/threats/vendors/cisco).

## Quick answers

**Is CVE-2020-3569 exploited in the wild?** Yes. CVE-2020-3569 is known to be exploited in the wild, first recorded on 3 November 2021. Treat it as urgent.

**How severe is CVE-2020-3569?** Critical severity, with a CVSS score of 8.6, published 3 November 2021.

**Which products and versions are affected?** Cisco IOS XR Software 6.1.4, 6.2.3, 6.3.3, 6.4.2, 6.5.3, 6.6.2, 6.6.3, 7.0.2, 7.1.2, 7.1.15.

**Is there a fix for CVE-2020-3569?** No fixed version is recorded yet. Check the vendor's advisory in the references below. If you run it, Junglewise drafts a mitigation that fits your setup and applies it once you approve, with senior security engineers behind it.

**How is CVE-2020-3569 attacked?** It is attacked over the network, in an operating system.

**Am I affected by CVE-2020-3569?** Check whether you run Cisco IOS XR. Junglewise does that check for you around the clock: connect your code, cloud and domains, and it matches new vulnerabilities like this one against what you actually run and tells you when one reaches you.

## Affected products

- Cisco IOS XR Software 6.1.4, 6.2.3, 6.3.3, 6.4.2, 6.5.3, 6.6.2, 6.6.3, 7.0.2, 7.1.2, 7.1.15

## Timeline

- 2021-11-03: disclosed
- 2021-11-03: kev added: Added to CISA Known Exploited Vulnerabilities Catalog

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