CVEs / CVE-2020-3566
CVE-2020-3566: Cisco IOS XR Software DVMRP Memory Exhaustion Vulnerability
- Known exploited in the CISA KEV catalog since 3 Nov 2021
- high 8.6 CVSS 3.1 (NVD)
- EPSS 3.7% chance of exploitation in the next 30 days, higher than 89% of CVEs (30 Oct 2026)
- Last changed at its sources
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Summary
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.
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.
Affected and fixed versions
| Product | Affected | Fixed in |
|---|---|---|
| Cisco Cisco IOS XR Software | n/a | — |
Exploitation
| In CISA KEV since | 3 Nov 2021 |
|---|---|
| Due date for US federal agencies | 3 May 2022 |
| Used in ransomware campaigns | Unknown |
| Required action | Apply updates per vendor instructions. |
Severity
| CVSS 3.1 | 8.6 highCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:HScored by NVD |
|---|---|
| Weakness | CWE-400, CWE-770 |
References
- CVE-2020-3566 on NVD
- CVE-2020-3566 in the CISA KEV catalog
- 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
Sources
Exploitation status from the CISA Known Exploited Vulnerabilities catalog. EPSS scores from FIRST. Descriptions, severity and references from the National Vulnerability Database. Open-source package versions from OSV (CC-BY 4.0). Text is shown as each source states it; Stackurity does not edit it. Check the vendor's advisory before acting.
This product uses data from the NVD API but is not endorsed or certified by the NVD.