CVE-2021-34714

Multiple Cisco Operating Systems Unidirectional Link Detection Denial of Service Vulnerability

State: Published
Severity: 7.4 High
Published: Sep 23, 2021
Updated: Nov 7, 2024
Reserved: Jun 15, 2021

Description

A vulnerability in the Unidirectional Link Detection (UDLD) feature of Cisco FXOS Software, Cisco IOS Software, Cisco IOS XE Software, Cisco IOS XR Software, and Cisco NX-OS Software could allow an unauthenticated, adjacent attacker to cause an affected device to reload. This vulnerability is due to improper input validation of the UDLD packets. An attacker could exploit this vulnerability by sending specifically crafted UDLD packets to an affected device. A successful exploit could allow the attacker to cause the affected device to reload, resulting in a denial of service (DoS) condition. Note: The UDLD feature is disabled by default, and the conditions to exploit this vulnerability are strict. An attacker must have full control of a directly connected device. On Cisco IOS XR devices, the impact is limited to the reload of the UDLD process.

Scores

CVSS	Score	Vector	Source
3.1	7.4 High	CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H	cisco

Weaknesses

CWE-20

Affected Products

Product	Versions
Cisco IOSCisco	n/aAffected

References

20210922 Multiple Cisco Operating Systems Unidirectional Link Detection Denial of Service Vulnerabilityvendor-advisory

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