vulnerability
Cisco XE: CVE-2023-20027: Cisco IOS XE Software Virtual Fragmentation Reassembly Denial of Service Vulnerability
| Severity | CVSS | Published | Added | Modified |
|---|---|---|---|---|
| 8 | (AV:N/AC:L/Au:N/C:N/I:N/A:C) | Mar 22, 2023 | Mar 23, 2023 | Dec 4, 2025 |
Description
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.
Solution
Explore Exposure Command
Confidently identify and prioritize exposures from endpoint to cloud with full attack surface visibility and threat-aware risk context.