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Case File

CVE-2021-34714

HIGH · CVSS 7.4 EPSS 0.39% Public Exploit

Source: NVD + CISA KEV + EPSS (historical backfill) · Published 2021-09-23 · Last synced 2026-08-04

CyberRota Analysis

This is a high severity vulnerability with a CVSS score of 7.4. It affects Cisco. Public exploit code or proof-of-concept references have been detected in its references. It may lead to a denial-of-service condition.

Public Exploit Signal

A public exploit, PoC, GitHub repository or Metasploit reference was detected for this CVE.

Detected Signals
exploit

Note: these links are listed for security research and verification purposes only.

CVE
CVE-2021-34714
Severity
HIGH
CVSS
7.4
EPSS
0.39%
Cisco

Original NVD 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.

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