Cisco IOS and IOS XE Software Link Layer Discovery Protocol Denial of Service Vulnerability (Cisco Cisco IOS)

CVE-2021-34703
MEDIUM 6.8

At a glance

Source
NVD
EPSS
EPSS 1.19 % Β· percentile 68 ()
State
PUBLISHED
Published
Updated
Assigner
cisco
NVD status
Modified

Description

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 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 attacker to cause the affected device to crash, resulting in a reload of the device.

Weaknesses (CWE)

  • CWE-456 β€” Missing Initialization of a Variable
  • CWE-665 β€” Improper Initialization

References

Scores

VersionScoreVectorScored by
CVSS 3.1MEDIUM 6.8CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:Hcisco
CVSS 3.1MEDIUM 6.8CVSS:3.1/AV:A/AC:L/PR:L/UI:N/S:C/C:N/I:N/A:HNVD Β· psirt@cisco.com (Secondary)
CVSS 3.1MEDIUM 6.5CVSS:3.1/AV:N/AC:L/PR:L/UI:N/S:U/C:N/I:N/A:HNVD Β· nvd@nist.gov (Primary)
CVSS 2.0MEDIUM 6.8AV:N/AC:L/Au:S/C:N/I:N/A:CNVD Β· nvd@nist.gov (Primary)

European references

Affected configurations (NVD CPE)

Affected products

ProductVersions
Cisco Β· Cisco IOSaffected n/a

Sources

SourceLicence
CVE List (CVEProject cvelistV5)CVE Program Terms of Use
EPSS (FIRST.org)FIRST β€” attribution requested
ENISA EUVDENISA β€” reproduction authorised, source acknowledged
NVD (NIST) via fkie-cad/nvd-json-data-feedsPublic domain β€” this product uses data from the NVD API but is not endorsed or certified by the NVD