CVE-2025-20311

Sept. 24, 2025, 6:15 p.m.

7.4
High

Description

A vulnerability in the handling of certain Ethernet frames in Cisco IOS XE Software for Catalyst 9000 Series Switches could allow an unauthenticated, adjacent attacker to cause an egress port to become blocked and drop all outbound traffic. This vulnerability is due to improper handling of crafted Ethernet frames. An attacker could exploit this vulnerability by sending crafted Ethernet frames through an affected switch. A successful exploit could allow the attacker to cause the egress port to which the crafted frame is forwarded to start dropping all frames, resulting in a denial of service (DoS) condition.

Product(s) Impacted

Vendor Product Versions
Cisco
  • Ios Xe
  • Catalyst 9000
  • *
  • *

Weaknesses

Common security weaknesses mapped to this vulnerability.

CWE-19
None
None

*CPE(s)

Affected systems and software identified for this CVE.

Type Vendor Product Version Update Edition Language Software Edition Target Software Target Hardware Other Information
a cisco ios_xe / / / / / catalyst_9000 / *
h cisco catalyst_9000 / / / / / / / /

CVSS Score

7.4 / 10

CVSS Data - 3.1

  • Attack Vector: ADJACENT_NETWORK
  • Attack Complexity: LOW
  • Privileges Required: NONE
  • Scope: CHANGED
  • Confidentiality Impact: NONE
  • Integrity Impact: NONE
  • Availability Impact: HIGH
  • CVSS:3.1/AV:A/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H

    View Vector String

Timeline

Published: Sept. 24, 2025, 6:15 p.m.
Last Modified: Sept. 24, 2025, 6:15 p.m.

Status : Received

CVE has been recently published to the CVE List and has been received by the NVD.

More info

Source

psirt@cisco.com

*Disclaimer: Some vulnerabilities do not have an associated CPE. To enhance the data, we use AI to infer CPEs based on CVE details. This is an automated process and might not always be accurate.