{"id":"CVE-2020-3566","published":"2020-08-29T16:15:09Z","modified":"2026-06-17T03:18:36Z","title":"Cisco IOS XR Software DVMRP Memory Exhaustion Vulnerability","vendor":"Cisco","product":"IOS XR","tier":"core","eol":null,"description":{"text":"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.","provenance":"source","from":"NVD"},"summary":{"text":"A flaw in the Distance Vector Multicast Routing Protocol (DVMRP) feature of Cisco IOS XR Software stems from insufficient queue management for Internet Group Management Protocol (IGMP) packets. An unauthenticated remote attacker who sends crafted IGMP traffic to an affected device can exhaust its process memory, destabilising other processes such as interior and exterior routing protocols, with no authentication or user interaction required.","provenance":"ai","model":"claude-haiku-5-5","generatedAt":"2026-10-23T07:13:47Z"},"cvss":{"score":8.6,"severity":"HIGH","version":"3.1","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H","provenance":"source","from":"NVD"},"epss":{"score":0.03702,"percentile":0.8971,"date":"2026-10-29","provenance":"source"},"kev":{"dateAdded":"2021-11-03","dueDate":"2022-05-03","ransomware":false,"requiredAction":"Apply updates per vendor instructions.","notes":"https://nvd.nist.gov/vuln/detail/CVE-2020-3566","provenance":"source"},"vulncheckKev":{"dateAdded":"2020-08-29","exploitedFirstSeen":"2020-08-29","ransomware":false,"evidence":[{"url":"https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-iosxr-dvmrp-memexh-dSmpdvfz","date":"2020-08-29"},{"url":"https://www.cisa.gov/sites/default/files/feeds/known_exploited_vulnerabilities.json","date":"2021-11-03"}],"evidenceTotal":2,"provenance":"source"},"exploited":true,"otx":{"pulseCount":50,"pulses":[{"name":"Actively_Exploited_Kev | Oct 29, 2026","url":"https://otx.alienvault.com/pulse/6ae20c1db17e7057ae7d9ad1","created":"2026-10-28"},{"name":"Actively_Exploited_Kev | Oct 28, 2026","url":"https://otx.alienvault.com/pulse/6ae0ba7e0e2a97ff7b218819","created":"2026-10-27"},{"name":"Actively_Exploited_Kev | Oct 27, 2026","url":"https://otx.alienvault.com/pulse/6adf68b85c3e852f3c111d18","created":"2026-10-26"},{"name":"Actively_Exploited_Kev | Oct 24, 2026","url":"https://otx.alienvault.com/pulse/6adb740e397c3ad4799aa4cd","created":"2026-10-23"},{"name":"Actively_Exploited_Kev | Oct 23, 2026","url":"https://otx.alienvault.com/pulse/6ada236fcfba2dfa730ea482","created":"2026-10-22"},{"name":"Actively_Exploited_Kev | Oct 22, 2026","url":"https://otx.alienvault.com/pulse/6ad8d33a077cbb5cab524d80","created":"2026-10-21"},{"name":"Actively_Exploited_Kev | Oct 21, 2026","url":"https://otx.alienvault.com/pulse/6ad78130c4d1ac2be83a8b6d","created":"2026-10-20"},{"name":"Actively_Exploited_Kev | Oct 20, 2026","url":"https://otx.alienvault.com/pulse/6ad62f63c24a405a3423cc13","created":"2026-10-19"},{"name":"Actively_Exploited_Kev | Oct 19, 2026","url":"https://otx.alienvault.com/pulse/6ad4dda174e5797d0bd238b7","created":"2026-10-18"},{"name":"Actively_Exploited_Kev | Oct 18, 2026","url":"https://otx.alienvault.com/pulse/6ad38c22e1848f8189d1c121","created":"2026-10-17"}],"provenance":"machine"},"cwes":[{"id":"CWE-770","name":"Allocation of Resources Without Limits or Throttling"},{"id":"CWE-400","name":"Uncontrolled Resource Consumption"}],"references":[{"url":"https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-iosxr-dvmrp-memexh-dSmpdvfz","tags":["Vendor Advisory"]},{"url":"https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-iosxr-dvmrp-memexh-dSmpdvfz","tags":["Vendor Advisory"]},{"url":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2020-3566","tags":["US Government Resource"]}],"techniques":[{"id":"T1190","name":"Exploit Public-Facing Application","tactics":["initial-access"],"provenance":"ai","basis":"ai-mapping","bases":["ai-mapping"],"basisDetail":"claude-haiku-5-5: Remote unauthenticated crafted network traffic exploits public-facing service","mappingType":"exploitation_technique","evidence":[{"from":"description","quote":"An attacker could exploit this vulnerability by sending crafted IGMP traffic to an affected device","start":317,"end":415}],"model":"claude-haiku-5-5","confidence":"medium","confidenceNote":"AI-mapped from the description (quote-validated, not expert-reviewed)"},{"id":"T1499.004","name":"Application or System Exploitation","tactics":["impact"],"provenance":"ai","basis":"ai-mapping","bases":["ai-mapping"],"basisDetail":"claude-haiku-5-5: Memory exhaustion causes application or system-level denial of service","mappingType":"primary_impact","evidence":[{"from":"description","quote":"A successful exploit could allow the attacker to cause memory exhaustion, resulting in instability of other processes","start":417,"end":534}],"model":"claude-haiku-5-5","confidence":"medium","confidenceNote":"AI-mapped from the description (quote-validated, not expert-reviewed)"}],"reports":[],"affected":[],"advisories":[],"euvd":{"id":"EUVD-2020-24837","url":"https://euvd.enisa.europa.eu/vulnerability/EUVD-2020-24837","exploited":true,"exploitedSince":"2021-11-03","provenance":"source"},"exploits":[],"exploitSources":null,"exploitRefs":[],"flow":[{"stage":"exploitation","techniques":["T1190"],"provenance":"ai"},{"stage":"primary","techniques":["T1499.004"],"provenance":"ai"}],"timeline":[{"date":"2020-08-29","kind":"published","label":"Published (NVD)","url":"https://nvd.nist.gov/vuln/detail/CVE-2020-3566","provenance":"source"},{"date":"2020-08-29","kind":"exploited-reported","label":"Exploitation first reported (VulnCheck KEV evidence)","url":"https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-iosxr-dvmrp-memexh-dSmpdvfz","provenance":"source"},{"date":"2021-11-03","kind":"kev","label":"Added to CISA KEV","url":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","provenance":"source"},{"date":"2021-11-03","kind":"euvd-exploited","label":"ENISA EUVD: exploited","url":"https://euvd.enisa.europa.eu/vulnerability/EUVD-2020-24837","provenance":"source"}],"speed":{"daysToPublicExploit":null,"firstExploitFrom":null,"daysToKev":431},"priority":{"score":62.0,"factors":[{"name":"In a KEV catalog","points":35.0,"detail":"listed in CISA KEV and VulnCheck KEV"},{"name":"Recent KEV listing","points":0.0,"detail":"added 2252 days ago"},{"name":"Known ransomware use","points":0.0,"detail":"not known"},{"name":"EPSS percentile","points":17.94,"detail":"percentile 0.8971"},{"name":"Named in threat reports","points":0.0,"detail":"0 reports"},{"name":"Public exploit code","points":0.0,"detail":"none found"},{"name":"Mentioned in OTX pulses","points":3.0,"detail":"50 pulses"},{"name":"CVSS severity","points":6.02,"detail":"base score 8.6"},{"name":"End-of-life product","points":0.0,"detail":"supported or unknown"}]}}