{"id":"CVE-2021-34778","url":"https://www.cyber-defence.io/tools/cve/CVE-2021-34778","generatedAt":"2026-10-27T20:54:01.030Z","title":"Multiple vulnerabilities exist in the Link Layer Discovery Protocol (LLDP) implementation for Cisco Small Business 220 Series Smart Switches.","description":"Multiple vulnerabilities exist in the Link Layer Discovery Protocol (LLDP) implementation for Cisco Small Business 220 Series Smart Switches. An unauthenticated, adjacent attacker could perform the following: Execute code on the affected device or cause it to reload unexpectedly Cause LLDP database corruption on the affected device For more information about these vulnerabilities, see the Details section of this advisory. Note: LLDP is a Layer 2 protocol. To exploit these vulnerabilities, an attacker must be in the same broadcast domain as the affected device (Layer 2 adjacent). Cisco has released firmware updates that address these vulnerabilities.","published":"2021-10-06T20:15:16.000Z","lastModified":"2026-06-17T03:56:33.000Z","status":"Modified","sourceIdentifier":"psirt@cisco.com","cvss":{"version":"3.1","score":4.3,"severity":"MEDIUM","vector":"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N"},"cwe":["CWE-120"],"affected":["cisco/business 220-8t-e-2g firmware","cisco/business 220-8p-e-2g firmware","cisco/business 220-8fp-e-2g firmware","cisco/business 220-16t-2g firmware","cisco/business 220-16p-2g firmware","cisco/business 220-24t-4g firmware","cisco/business 220-24p-4g firmware","cisco/business 220-24fp-4g firmware","cisco/business 220-48t-4g firmware","cisco/business 220-48p-4g firmware","cisco/business 220-24t-4x firmware","cisco/business 220-24p-4x firmware","cisco/business 220-24fp-4x firmware","cisco/business 220-48t-4x firmware","cisco/business 220-48p-4x firmware","cisco/business 220-48fp-4x firmware"],"epss":{"score":0.00411,"percentile":0.35123,"date":"2026-10-26","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"low","text":"Lower severity and a low EPSS score (0.41%). Track it; it rarely justifies an emergency change on its own."},"changes":[],"references":[{"url":"https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-sb220-lldp-multivuls-mVRUtQ8T","tags":["Vendor Advisory"],"source":"psirt@cisco.com"},{"url":"https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-sb220-lldp-multivuls-mVRUtQ8T","tags":["Vendor Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2021-34778","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}