{"id":"CVE-2020-3566","aliases":["EUVD-2020-24837","GHSA-mr9v-hqxh-vq2j"],"status":"published","title":"Cisco IOS XR Software DVMRP Memory Exhaustion Vulnerability","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.","severity":{"version":"3.1","score":8.6,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H","level":"high","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-09","score":0.03702,"percentile":0.89818,"model":"v2026.06.15"},"facts":{"in_kev":true,"known_exploited":true,"public_exploit":false,"fix_available":false},"cwes":["CWE-400","CWE-770"],"published":"2020-08-29T15:15:13Z","modified":"2026-06-17T03:18:36Z","kev":{"date_added":"2021-11-03","due_date":"2022-05-03","required_action":"Apply updates per vendor instructions.","known_ransomware_use":"Unknown"},"exploitation":[{"source":"euvd","since":"2021-11-03"},{"source":"kev","since":"2021-11-03"}],"products":[{"vendor":"cisco","product":"cisco ios xr software"},{"vendor":"cisco","product":"ios xr"},{"vendor":"cisco","product":"ios_xr"}],"references":[{"url":"https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-iosxr-dvmrp-memexh-dSmpdvfz","tags":["vendor-advisory","x_refsource_CISCO","x_transferred","Vendor Advisory"]},{"url":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2020-3566","tags":["government-resource","US Government Resource"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2020-3566"},{"url":"https://github.com/advisories/GHSA-mr9v-hqxh-vq2j"}],"sources":{"cve":[{"id":"CVE-2020-3566","title":"Cisco IOS XR Software DVMRP Memory Exhaustion Vulnerability","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.","status":"published","published":"2020-08-29T15:15:13.627Z","modified":"2025-10-21T23:35:37.484Z","cvss":[{"version":"3.1","score":8.6,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H","level":"high","assessor":"cna"}],"cwes":["CWE-400"],"updated_at":"2026-11-02T14:35:51.923913Z"}],"euvd":[{"id":"EUVD-2020-24837","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.","status":"published","published":"2020-08-29T15:15:13Z","modified":"2025-10-21T23:35:37Z","cvss":[{"version":"3.1","score":8.6,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H","level":"high"}],"exploited_since":"2021-11-03","updated_at":"2026-11-02T20:31:24.816637Z"}],"ghsa":[{"id":"GHSA-mr9v-hqxh-vq2j","title":"A vulnerability in the Distance Vector Multicast Routing Protocol (DVMRP) feature of Cisco IOS XR...","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.","status":"published","published":"2022-05-24T17:26:56Z","modified":"2025-10-22T00:33:02Z","cvss":[{"version":"3.1","score":7.5,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H","level":"high"}],"cwes":["CWE-400","CWE-770"],"updated_at":"2026-11-02T15:04:07.112106Z"}],"kev":[{"id":"CVE-2020-3566","title":"Cisco IOS XR Software DVMRP Memory Exhaustion Vulnerability","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.","cwes":["CWE-400"],"kev":{"date_added":"2021-11-03","due_date":"2022-05-03","required_action":"Apply updates per vendor instructions.","known_ransomware_use":"Unknown"},"updated_at":"2026-11-02T17:00:17.050017Z"}],"nvd":[{"id":"CVE-2020-3566","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.","status":"published","published":"2020-08-29T16:15:09.797Z","modified":"2026-06-17T03:18:36.94Z","cvss":[{"version":"3.1","score":8.6,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H","level":"high","assessor":"secondary"},{"version":"3.1","score":8.6,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H","level":"high","assessor":"primary"},{"version":"2.0","score":7.8,"vector":"AV:N/AC:L/Au:N/C:N/I:N/A:C","level":"high","assessor":"primary"}],"cwes":["CWE-400","CWE-770"],"updated_at":"2026-11-02T14:06:13.600965Z"}]}}