cbcvebase.
CVE-2020-3569
published 2020-09-23

CVE-2020-3569: Multiple vulnerabilities in the Distance Vector Multicast Routing Protocol (DVMRP) feature of Cisco IOS XR Software could allow an unauthenticated, remote…

PriorityP180high8.6CVSS 3.1
AVNACLPRNUINSCCNINAH
KEVITW
CISA Known Exploited Vulnerabilitydue 2022-05-03
Exploited in the wild
EPSS
3.29%
87.1th percentile
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.

Affected

14 ranges
VendorProductVersion rangeFixed in
ciscocisco_ios_xr_software
ciscoios_xr< 6.5.26.5.2
ciscoios_xr
ciscoios_xr
ciscoios_xr
ciscoios_xr
ciscoios_xr
ciscoios_xr
ciscoios_xr
ciscoios_xr
ciscoios_xr
ciscoios_xr
ciscoios_xr
ciscoios_xr

Detection & IOCsextracted from sources · hover to see the quote

commandlpts pifib hardware police flow igmp rate <rate>
commandipv4 access-list deny igmp any any dvmrp
  • Monitor for crafted IGMP packets (specifically DVMRP traffic) sent to Cisco IOS XR devices; exploitation manifests as IGMP process crash or abnormal memory consumption in the IGMP process.
  • Check if multicast routing is enabled on any interface using 'show igmp interface'; a non-empty output confirms the device is exposed and should be prioritized for detection/patching.
  • Secondary impact indicator: instability or crashes in interior/exterior routing protocols (BGP, OSPF, etc.) on an IOS XR device may indicate successful IGMP memory exhaustion exploitation.
  • ·Only Cisco IOS XR devices with multicast routing actively configured on at least one interface are vulnerable; devices without multicast routing enabled are not affected.
  • ·The rate-limiting mitigation (lpts pifib hardware police flow igmp rate) does not prevent exploitation but only slows it by reducing IGMP traffic below the current average rate, increasing time-to-exploit.
  • ·Cisco Bug IDs associated with CVE-2020-3569 are CSCvr86414, CSCvv54838, and CSCvv60110; use these for patch tracking and SMU identification.

CVSS provenance

nvdv3.18.6HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H
nvdv2.05.0MEDIUMAV:N/AC:L/Au:N/C:N/I:N/A:P
vulncheck8.6HIGH
cisa8.6HIGH
vendor_cisco8.6HIGH
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