CVE-2023-20027 HIGH

CVE-2023-20027: Cisco IOS XE Software Virtual Fragmentation Reassembly Denial of Service Vulnerability

Vendor Cisco
Product Cisco IOS XE Software
Weakness CWE-416
Published March 23, 2023
Last update October 28, 2024

CVSS base score

8.6/10
Attack vector Network
Attack complexity Low
Privileges required None
User interaction None
Confidentiality None
Integrity None

CVSS vector

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H

What the vulnerability does

01Description

A vulnerability in the implementation of the IPv4 Virtual Fragmentation Reassembly (VFR) feature of Cisco IOS XE Software could allow an unauthenticated, remote attacker to cause a denial of service (DoS) condition on an affected device. This vulnerability is due to improper reassembly of large packets that occurs when VFR is enabled on either a tunnel interface or on a physical interface that is configured with a maximum transmission unit (MTU) greater than 4,615 bytes. An attacker could exploit this vulnerability by sending fragmented packets through a VFR-enabled interface on an affected device. A successful exploit could allow the attacker to cause the device to reload, resulting in a DoS condition.

Key dates

02Disclosure timeline

March 23, 2023 CVE published
October 28, 2024 Record updated