Cisco · IOS XR
CVE-2020-3569
Cisco IOS XR Software DVMRP Memory Exhaustion Vulnerabilities
What it is
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.
CISA: 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.
What to do
Apply updates per vendor instructions.
Deadline for US federal agencies: May 3, 2022
More exploited flaws from Cisco
| Added | Vulnerability | Product | Severity | Attack chance |
|---|---|---|---|---|
| May 23, 2022 | Open Port | IOS XR | Medium 6.5 | 11% |
| Mar 25, 2022 | Border Gateway Protocol (BGP) Denial-of-Service | IOS XR | Medium 5.9 | 3.3% |
| Mar 25, 2022 | Border Gateway Protocol (BGP) Denial-of-Service | IOS XR | High 7.5 | 5.7% |
| Nov 3, 2021 | Software Discovery Protocol Format String | IOS XR | High 8.8 | 12% |
| Nov 3, 2021 | Software DVMRP Memory Exhaustion | IOS XR | High 8.6 | 3.7% |
| Oct 14, 2026 | Relative Path Traversal | Secure Email Gateway | Critical 9.8 | 2.2% |
| Sep 30, 2026 | Hex Encoding | Catalyst SD-WAN Manager | Critical 9.8 | 39% |
| Sep 16, 2026 | Incorrect Use of Privileged APIs | Identity Services Engine | Critical 10.0 | 76% |
Sources: Known Exploited Vulnerabilities (CISA, public domain), CVE records (cve.org) and EPSS (FIRST). The chance of attacks is the EPSS estimate that someone will try to exploit the flaw in the next 30 days.