6.5
CVSSv3

CVE-2021-34703

Published: 23/09/2021 Updated: 07/11/2023
CVSS v2 Base Score: 6.8 | Impact Score: 6.9 | Exploitability Score: 8
CVSS v3 Base Score: 6.5 | Impact Score: 3.6 | Exploitability Score: 2.8
VMScore: 605
Vector: AV:N/AC:L/Au:S/C:N/I:N/A:C

Vulnerability Summary

A vulnerability in the Link Layer Discovery Protocol (LLDP) message parser of Cisco IOS Software and Cisco IOS XE Software could allow an malicious user to trigger a reload of an affected device, resulting in a denial of service (DoS) condition. This vulnerability is due to improper initialization of a buffer. An attacker could exploit this vulnerability via any of the following methods: An authenticated, remote attacker could access the LLDP neighbor table via either the CLI or SNMP while the device is in a specific state. An unauthenticated, adjacent attacker could corrupt the LLDP neighbor table by injecting specific LLDP frames into the network and then waiting for an administrator of the device or a network management system (NMS) managing the device to retrieve the LLDP neighbor table of the device via either the CLI or SNMP. An authenticated, adjacent attacker with SNMP read-only credentials or low privileges on the device CLI could corrupt the LLDP neighbor table by injecting specific LLDP frames into the network and then accessing the LLDP neighbor table via either the CLI or SNMP. A successful exploit could allow the malicious user to cause the affected device to crash, resulting in a reload of the device.

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cisco ios

cisco ios_xe

Vendor Advisories

A vulnerability in the Link Layer Discovery Protocol (LLDP) message parser of Cisco IOS Software and Cisco IOS XE Software could allow an attacker to trigger a reload of an affected device, resulting in a denial of service (DoS) condition This vulnerability is due to improper initialization of a buffer An attacker could exploit this vulnerability ...