7.4

CVE-2021-34714: cisco cisco_ios Improper Input Validation

CVSS: 7.4v3.1HighModified
Published 23-09-2021Last modified 07-11-2024
Open JSON

Vulnerability summary

CVE-2021-34714 is a high (CVSS 7.4) Improper Input Validation vulnerability in cisco cisco_ios. EPSS estimates a 0.39% chance of exploitation in the next 30 days, higher than 31.3% of scored vulnerabilities.

Overall risk
30/100
0100
Medium · default modelHow is this calculated?
CVSS score
7.4/10
010
High · v3.1 (CVE.org)
EPSS score
0.39%
0%100%
Low · 0.00 pp in 30 days
KEVNot listedIn no KEV catalog
RansomwareNone recordedNo known use recorded
Public exploits0No public exploits recorded

Timeline

  1. 23-09-2021
    PublishedVulnerability first disclosed.
  2. 07-11-2024
    Last modifiedVulnerability information updated.

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.

CVSS metrics

3 scores · 2 sources · 2 versions

EPSS trend

Probability

0.39%

Chance of exploitation in the next 30 days

Percentile

31%

Versus all other CVEs

30-day change

0.00 pp

From 0.39% on 18-09-2026

18-09-202618-10-2026
EPSS score
0.39%

Known exploited

Compare KEV catalogs

Not in any of the 3 tracked catalogs.

Public exploits

0 found

No public exploits indexed.

Weaknesses

CWE · root cause

Affected systems

Cisco7 products
  • cisco_iosn/a
  • firepower_extensible_operating_system≤ 8.4\(3.115\) | ≤ 7.0\(3\)i7\(9\) | ≤ 7.3\(8\)n1\(1\) | ≤ 3.2\(3o\)a | ≤ 4.1\(1a\)a
  • fxos≥ 2.2, < 2.2.2.148 | ≥ 2.3, < 2.3.1.216 | ≥ 2.4, < 2.4.1.273 | ≥ 2.6, < 2.6.1.224 | ≥ 2.7, < 2.7.1.143 | ≥ 2.8, < 2.8.1.143 | ≥ 2.9, < 2.9.1.135
  • ios≤ 8.4\(3.115\) | ≤ 7.0\(3\)i7\(9\) | ≤ 7.3\(8\)n1\(1\) | ≤ 3.2\(3o\)a | ≤ 4.1\(1a\)a
  • ios_xe≤ 8.4\(3.115\) | ≤ 7.0\(3\)i7\(9\) | ≤ 7.3\(8\)n1\(1\) | ≤ 3.2\(3o\)a | ≤ 4.1\(1a\)a

1 vendor · 7 products

References

1 links