1. Home
  2. Vulnerabilities
  3. CVE-2020-3566
Known Exploited Vulnerability
8.6
HIGH CVSS 3.1
CVE-2020-3566
Cisco IOS XR Software DVMRP Memory Exhaustion Vulnerability - [Actively Exploited]
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.

INFO

Published Date :

Aug. 29, 2020, 4:15 p.m.

Last Modified :

Oct. 28, 2025, 1:53 p.m.

Remotely Exploit :

Yes !

Source :

[email protected]
CISA Notification
CISA KEV (Known Exploited Vulnerabilities)

For the benefit of the cybersecurity community and network defenders—and to help every organization better manage vulnerabilities and keep pace with threat activity—CISA maintains the authoritative source of vulnerabilities that have been exploited in the wild.

Description :

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.

Required Action :

Apply updates per vendor instructions.

Notes :

https://nvd.nist.gov/vuln/detail/CVE-2020-3566

Affected Products

The following products are affected by CVE-2020-3566 vulnerability. Even if cvefeed.io is aware of the exact versions of the products that are affected, the information is not represented in the table below.

ID Vendor Product Action
1 Cisco ios_xr
2 Cisco asr_9001
3 Cisco asr_9006
4 Cisco asr_9010
5 Cisco asr_9904
6 Cisco asr_9912
7 Cisco asr_9922
8 Cisco asr_9901
9 Cisco asr_9906
10 Cisco asr_9910
: Total Affected Vendor : 1 | Products : 10
CVSS Scores
The Common Vulnerability Scoring System is a standardized framework for assessing the severity of vulnerabilities in software and systems. We collect and displays CVSS scores from various sources for each CVE.
Score Version Severity Vector Exploitability Score Impact Score Source
CVSS 2.0 HIGH [email protected]
CVSS 3.1 HIGH [email protected]
CVSS 3.1 HIGH [email protected]
Solution
This information is provided by the 3rd party feeds.
  • Upgrade to the relevant fixed version referenced in Cisco bug IDs CSCvr86414, CSCvv54838
Public PoC/Exploit Available at Github

CVE-2020-3566 has a 3 public PoC/Exploit available at Github. Go to the Public Exploits tab to see the list.

References to Advisories, Solutions, and Tools

Here, you will find a curated list of external links that provide in-depth information, practical solutions, and valuable tools related to CVE-2020-3566.

URL Resource
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-iosxr-dvmrp-memexh-dSmpdvfz Vendor Advisory
https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-iosxr-dvmrp-memexh-dSmpdvfz Vendor Advisory
https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2020-3566 US Government Resource
CWE - Common Weakness Enumeration

While CVE identifies specific instances of vulnerabilities, CWE categorizes the common flaws or weaknesses that can lead to vulnerabilities. CVE-2020-3566 is associated with the following CWEs:

Common Attack Pattern Enumeration and Classification (CAPEC)

Common Attack Pattern Enumeration and Classification (CAPEC) stores attack patterns, which are descriptions of the common attributes and approaches employed by adversaries to exploit the CVE-2020-3566 weaknesses.

CAPEC-147: XML Ping of the Death XML Ping of the Death CAPEC-227: Sustained Client Engagement Sustained Client Engagement CAPEC-492: Regular Expression Exponential Blowup Regular Expression Exponential Blowup CAPEC-125: Flooding Flooding CAPEC-130: Excessive Allocation Excessive Allocation CAPEC-147: XML Ping of the Death XML Ping of the Death CAPEC-197: Exponential Data Expansion Exponential Data Expansion CAPEC-229: Serialized Data Parameter Blowup Serialized Data Parameter Blowup CAPEC-230: Serialized Data with Nested Payloads Serialized Data with Nested Payloads CAPEC-231: Oversized Serialized Data Payloads Oversized Serialized Data Payloads CAPEC-469: HTTP DoS HTTP DoS CAPEC-482: TCP Flood TCP Flood CAPEC-486: UDP Flood UDP Flood CAPEC-487: ICMP Flood ICMP Flood CAPEC-488: HTTP Flood HTTP Flood CAPEC-489: SSL Flood SSL Flood CAPEC-490: Amplification Amplification CAPEC-491: Quadratic Data Expansion Quadratic Data Expansion CAPEC-493: SOAP Array Blowup SOAP Array Blowup CAPEC-494: TCP Fragmentation TCP Fragmentation CAPEC-495: UDP Fragmentation UDP Fragmentation CAPEC-496: ICMP Fragmentation ICMP Fragmentation CAPEC-528: XML Flood XML Flood

We scan GitHub repositories to detect new proof-of-concept exploits. Following list is a collection of public exploits and proof-of-concepts, which have been published on GitHub (sorted by the most recently updated).

Profile Photo
santosomar/kev_checker

A basic Python program to check Cybersecurity & Infrastructure Security Agency (CISA) Known Exploited Vulnerabilities (KEV) Catalog

Python

Updated: 3 months, 2 weeks ago
20 stars 3 fork 3 watcher
Born at : Feb. 9, 2023, 5:26 p.m. This repo has been linked 14 different CVEs too.
Profile Photo
Ostorlab/KEV

Ostorlab KEV: One-command to detect most remotely known exploitable vulnerabilities. Sourced from CISA KEV, Google's Tsunami, Ostorlab's Asteroid and Bug Bounty programs.

cisa-kev vulnerability 0day cisa exploits

Updated: 3 weeks, 3 days ago
588 stars 42 fork 42 watcher
Born at : April 19, 2022, 8:58 a.m. This repo has been linked 1290 different CVEs too.
Profile Photo
alphaSeclab/sec-daily-2020

2020年发布到阿尔法实验室微信公众号的所有安全资讯汇总

Updated: 5 months, 4 weeks ago
41 stars 15 fork 15 watcher
Born at : Jan. 11, 2021, 2:08 a.m. This repo has been linked 190 different CVEs too.

Results are limited to the first 15 repositories due to potential performance issues.

The following list is the news that have been mention CVE-2020-3566 vulnerability anywhere in the article.

Results are limited to the first 20 news articles due to potential performance issues.

The following table lists the changes that have been made to the CVE-2020-3566 vulnerability over time.

Vulnerability history details can be useful for understanding the evolution of a vulnerability, and for identifying the most recent changes that may impact the vulnerability's severity, exploitability, or other characteristics.

  • Modified Analysis by [email protected]

    Oct. 28, 2025

    Action Type Old Value New Value
    Added Reference Type CISA-ADP: https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2020-3566 Types: US Government Resource
  • CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0

    Oct. 22, 2025

    Action Type Old Value New Value
    Added Reference https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2020-3566
  • CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0

    Oct. 21, 2025

    Action Type Old Value New Value
    Removed Reference https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2020-3566
  • CVE Modified by 134c704f-9b21-4f2e-91b3-4a467353bcc0

    Oct. 21, 2025

    Action Type Old Value New Value
    Added Reference https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2020-3566
  • Modified Analysis by [email protected]

    Feb. 24, 2025

    Action Type Old Value New Value
  • CVE Modified by af854a3a-2127-422b-91ae-364da2661108

    Nov. 21, 2024

    Action Type Old Value New Value
    Added Reference https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-iosxr-dvmrp-memexh-dSmpdvfz
  • Modified Analysis by [email protected]

    Jul. 26, 2024

    Action Type Old Value New Value
    Removed CVSS V3.1 NIST AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
    Added CVSS V3.1 NIST AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
  • CVE Modified by [email protected]

    May. 14, 2024

    Action Type Old Value New Value
  • CVE Modified by [email protected]

    Nov. 07, 2023

    Action Type Old Value New Value
    Removed CVSS V3 Cisco Systems, Inc. AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
    Added CVSS V3.1 Cisco Systems, Inc. AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
  • Reanalysis by [email protected]

    Oct. 21, 2022

    Action Type Old Value New Value
    Removed CWE NIST CWE-400
    Added CWE NIST CWE-770
  • Initial Analysis by [email protected]

    Sep. 04, 2020

    Action Type Old Value New Value
    Added CVSS V2 NIST (AV:N/AC:L/Au:N/C:N/I:N/A:C)
    Added CVSS V3.1 NIST AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H
    Changed Reference Type https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-iosxr-dvmrp-memexh-dSmpdvfz No Types Assigned https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-iosxr-dvmrp-memexh-dSmpdvfz Vendor Advisory
    Added CWE NIST CWE-400
    Added CPE Configuration AND OR *cpe:2.3:o:cisco:ios_xr:6.4.2:*:*:*:*:*:*:* OR cpe:2.3:h:cisco:asr_9001:-:*:*:*:*:*:*:* cpe:2.3:h:cisco:asr_9006:-:*:*:*:*:*:*:* cpe:2.3:h:cisco:asr_9010:-:*:*:*:*:*:*:* cpe:2.3:h:cisco:asr_9901:-:*:*:*:*:*:*:* cpe:2.3:h:cisco:asr_9904:-:*:*:*:*:*:*:* cpe:2.3:h:cisco:asr_9906:-:*:*:*:*:*:*:* cpe:2.3:h:cisco:asr_9910:-:*:*:*:*:*:*:* cpe:2.3:h:cisco:asr_9912:-:*:*:*:*:*:*:* cpe:2.3:h:cisco:asr_9922:-:*:*:*:*:*:*:*
EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days. Following chart shows the EPSS score history of the vulnerability.
Vulnerability Scoring Details
Base CVSS Score: 8.6
Attack Vector
Attack Complexity
Privileges Required
User Interaction
Scope
Confidentiality Impact
Integrity Impact
Availability Impact
Base CVSS Score: 7.8
Access Vector
Access Complexity
Authentication
Confidentiality Impact
Integrity Impact
Availability Impact
Exploit Prediction

EPSS is a daily estimate of the probability of exploitation activity being observed over the next 30 days.

15.10 }} -3.86%

score

0.94275

percentile