{"id":"CVE-2020-3118","published":"2020-02-05T18:15:10Z","modified":"2026-06-17T03:17:23Z","title":"Cisco IOS XR Software Discovery Protocol Format String Vulnerability","vendor":"Cisco","product":"IOS XR","tier":"core","eol":null,"description":{"text":"A vulnerability in the Cisco Discovery Protocol implementation for Cisco IOS XR Software could allow an unauthenticated, adjacent attacker to execute arbitrary code or cause a reload on an affected device. The vulnerability is due to improper validation of string input from certain fields in Cisco Discovery Protocol messages. An attacker could exploit this vulnerability by sending a malicious Cisco Discovery Protocol packet to an affected device. A successful exploit could allow the attacker to cause a stack overflow, which could allow the attacker to execute arbitrary code with administrative privileges on an affected device. Cisco Discovery Protocol is a Layer 2 protocol. To exploit this vulnerability, an attacker must be in the same broadcast domain as the affected device (Layer 2 adjacent).","provenance":"source","from":"NVD"},"summary":{"text":"A flaw in the Cisco Discovery Protocol implementation of Cisco IOS XR Software, caused by improper validation of string input from certain fields in CDP messages, allows arbitrary code execution or a device reload. An unauthenticated attacker in the same broadcast domain (Layer 2 adjacent) can exploit it by sending a malicious CDP packet to the affected device, which can cause a stack overflow that runs code with administrative privileges.","provenance":"ai","model":"claude-haiku-5-5","generatedAt":"2026-10-23T07:10:45Z"},"cvss":{"score":8.8,"severity":"HIGH","version":"3.1","vector":"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H","provenance":"source","from":"NVD"},"epss":{"score":0.11685,"percentile":0.96049,"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-2020-3118","provenance":"source"},"vulncheckKev":{"dateAdded":"2020-10-20","exploitedFirstSeen":"2020-10-20","ransomware":false,"evidence":[{"url":"https://cisa.gov/news-events/cybersecurity-advisories/aa20-275a","date":"2020-10-20"},{"url":"https://media.defense.gov/2020/Oct/20/2002519884/-1/-1/0/CSA_CHINESE_EXPLOIT_VULNERABILITIES_UOO179811.PDF","date":"2020-10-20"},{"url":"https://us-cert.cisa.gov/ncas/alerts/aa20-275a","date":"2020-10-20"},{"url":"https://www.cisa.gov/sites/default/files/feeds/known_exploited_vulnerabilities.json","date":"2021-11-03"}],"evidenceTotal":4,"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-787","name":"Out-of-bounds Write"},{"id":"CWE-134","name":"Use of Externally-Controlled Format String"}],"references":[{"url":"http://packetstormsecurity.com/files/156203/Cisco-Discovery-Protocol-CDP-Remote-Device-Takeover.html","tags":["Third Party Advisory","VDB Entry"]},{"url":"https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20200205-iosxr-cdp-rce","tags":["Vendor Advisory"]},{"url":"http://packetstormsecurity.com/files/156203/Cisco-Discovery-Protocol-CDP-Remote-Device-Takeover.html","tags":["Third Party Advisory","VDB Entry"]},{"url":"https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20200205-iosxr-cdp-rce","tags":["Vendor Advisory"]},{"url":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog?field_cve=CVE-2020-3118","tags":["US Government Resource"]}],"techniques":[{"id":"T1210","name":"Exploitation of Remote Services","tactics":["lateral-movement"],"provenance":"ai","basis":"ai-mapping","bases":["ai-mapping"],"basisDetail":"claude-haiku-5-5: Adjacent network packet exploits remote service","mappingType":"exploitation_technique","evidence":[{"from":"description","quote":"An attacker could exploit this vulnerability by sending a malicious Cisco Discovery Protocol packet","start":328,"end":427}],"model":"claude-haiku-5-5","confidence":"medium","confidenceNote":"AI-mapped from the description (quote-validated, not expert-reviewed)"},{"id":"T1059","name":"Command and Scripting Interpreter","tactics":["execution"],"provenance":"ai","basis":"ai-mapping","bases":["ai-mapping"],"basisDetail":"claude-haiku-5-5: Arbitrary code execution with admin privileges","mappingType":"primary_impact","evidence":[{"from":"description","quote":"could allow the attacker to execute arbitrary code with administrative privileges","start":530,"end":611}],"model":"claude-haiku-5-5","confidence":"medium","confidenceNote":"AI-mapped from the description (quote-validated, not expert-reviewed)"}],"reports":[],"affected":[],"advisories":[],"euvd":{"id":"EUVD-2020-24389","url":"https://euvd.enisa.europa.eu/vulnerability/EUVD-2020-24389","exploited":true,"exploitedSince":"2021-11-03","provenance":"source"},"exploits":[],"exploitSources":null,"exploitRefs":["http://packetstormsecurity.com/files/156203/Cisco-Discovery-Protocol-CDP-Remote-Device-Takeover.html"],"flow":[{"stage":"exploitation","techniques":["T1210"],"provenance":"ai"},{"stage":"primary","techniques":["T1059"],"provenance":"ai"}],"timeline":[{"date":"2020-02-05","kind":"published","label":"Published (NVD)","url":"https://nvd.nist.gov/vuln/detail/CVE-2020-3118","provenance":"source"},{"date":"2020-10-20","kind":"exploited-reported","label":"Exploitation first reported (VulnCheck KEV evidence)","url":"https://cisa.gov/news-events/cybersecurity-advisories/aa20-275a","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-2020-24389","provenance":"source"}],"speed":{"daysToPublicExploit":null,"firstExploitFrom":null,"daysToKev":637},"priority":{"score":68.4,"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 2200 days ago"},{"name":"Known ransomware use","points":0.0,"detail":"not known"},{"name":"EPSS percentile","points":19.21,"detail":"percentile 0.9605"},{"name":"Named in threat reports","points":0.0,"detail":"0 reports"},{"name":"Public exploit code","points":5.0,"detail":"1 NVD exploit link"},{"name":"Mentioned in OTX pulses","points":3.0,"detail":"50 pulses"},{"name":"CVSS severity","points":6.16,"detail":"base score 8.8"},{"name":"End-of-life product","points":0.0,"detail":"supported or unknown"}]}}