{"cve":"CVE-2021-34775","nvd":{"published":"2021-10-06T20:15:14.447","modified":"2026-06-17T03:56:32.600","status":"Modified","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.","cvss_v4":null,"cvss_v3":{"version":"3.1","vector":"CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N","score":4.3},"cwes":["CWE-120"],"references":["https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-sb220-lldp-multivuls-mVRUtQ8T","https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-sb220-lldp-multivuls-mVRUtQ8T"],"products":["cisco:business_220-16p-2g_firmware","cisco:business_220-16t-2g_firmware","cisco:business_220-24fp-4g_firmware","cisco:business_220-24fp-4x_firmware","cisco:business_220-24p-4g_firmware","cisco:business_220-24p-4x_firmware","cisco:business_220-24t-4g_firmware","cisco:business_220-24t-4x_firmware","cisco:business_220-48fp-4x_firmware","cisco:business_220-48p-4g_firmware","cisco:business_220-48p-4x_firmware","cisco:business_220-48t-4g_firmware","cisco:business_220-48t-4x_firmware","cisco:business_220-8fp-e-2g_firmware","cisco:business_220-8p-e-2g_firmware","cisco:business_220-8t-e-2g_firmware"],"source":"nvd","synced_at":"2026-10-19T21:23:41.316049955+00:00"},"epss":{"cve":"CVE-2021-34775","score":0.00411,"percentile":0.35405,"date":"2026-10-31"},"kev":null,"osv":[],"attribution":["This product uses the NVD API but is not endorsed or certified by the NVD.","EPSS scores: FIRST Exploit Prediction Scoring System, https://www.first.org/epss","Known exploited vulnerabilities: CISA Known Exploited Vulnerabilities Catalog, https://www.cisa.gov/known-exploited-vulnerabilities-catalog","Package advisories: OSV (https://osv.dev), from the GitHub Advisory Database, PyPA, Go, RustSec and other ecosystem databases, under CC-BY 4.0 or CC0","CVE records: the CVE Program's CVE List (https://www.cve.org), under its terms of use (https://www.cve.org/Legal/TermsOfUse). CVE is a registered trademark of The MITRE Corporation; this product is not affiliated with the CVE Program."]}