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CVE-2020-3569

8.6, high Known exploited

Cisco IOS XR Software DVMRP Memory Exhaustion Vulnerability

CVSS
8.6, high high CVSS v3.1
EPSS, next 30 days
3% higher than 88.4% of scored CVEs
Exploitation
Confirmed in the wild
Published
23 Sept 20206 years ago

Known exploited

CISA added this to the Known Exploited Vulnerabilities Catalog on 3 Nov 2021. US federal agencies had to remediate by 3 May 2022, a deadline that has passed.

Required action. Apply updates per vendor instructions.

Description

Multiple vulnerabilities in the Distance Vector Multicast Routing Protocol (DVMRP) feature of Cisco IOS XR Software could allow an unauthenticated, remote attacker to either immediately crash the Internet Group Management Protocol (IGMP) process or make it consume available memory and eventually crash. The memory consumption may negatively impact other processes that are running on the device. These vulnerabilities are due to the incorrect handling of IGMP packets. An attacker could exploit these vulnerabilities by sending crafted IGMP traffic to an affected device. A successful exploit could allow the attacker to immediately crash the IGMP process or cause memory exhaustion, resulting in other processes becoming unstable. These processes may include, but are not limited to, interior and exterior routing protocols. Cisco will release software updates that address these vulnerabilities.

Details

Vendor
Cisco
Product
Cisco IOS XR Software
Weakness
CWE-400 (opens in a new tab)
Status
Analyzed
Updated
17 Jun 2026
Assigner
psirt@cisco.com

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H

References 2

The kind is read from NVD's tags where present and from the shape of the URL otherwise, so treat it as a hint.

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Beyond this page

Is CVE-2020-3569 in your network?

This page tells you how dangerous CVE-2020-3569 is out there. Whether it sits on one of your devices, only a scan of your own network can tell. That is what our systems do, every day, for the companies we protect.

CVE-2020-3569 is in the CISA catalogue of exploited vulnerabilities: attackers are already exploiting it.

  • EXYS7600 OCELOT

    Find it before attackers do

    Ocelot scans your network on a schedule and reports every vulnerability it finds by its CVE identifier, with its CVSS score and how many of your hosts are affected. A finding like CVE-2020-3569 comes with the devices to patch.

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  • EXYS7950 KONDRA

    Detect it if it's exploited

    Until the patch is applied, Kondra monitors your network, events and endpoints in real time. It keeps an inventory of the software installed on every endpoint, and its anomaly detection rules flag what an attacker does once inside.

    Learn more about EXYS7950 KONDRA
Check your exposure

Assembled from the NVD 2.0 API, the CISA Known Exploited Vulnerabilities Catalog and FIRST EPSS. Scores are as of our last collection on 17 Oct 2026, not the live upstream state.