CVE-2021-34777

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.

• CWE-120
• CWE-120

• https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-sb220-lldp-multivuls-mVRUtQ8TVendor Advisory
• https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-sb220-lldp-multivuls-mVRUtQ8TVendor Advisory

Published

Oct 6, 2021

Last Modified

Jun 17, 2026

Status

Modified

• How Strix found a critical auth bypass in etcdStrix autonomously discovered a critical authentication bypass in etcd, later designated CVE-2026-33413.
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