Use After Free in Cisco 1000 Integrated Services Router

CVE-2023-20027

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.

Vulnerability class: Use-After-Free

Published · last modified .

CVSS v3 metric

CVSS v3 base score 8.6 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H.

EPSS exploit prediction

EPSS: 0.010 (62.2th percentile), scored .

Very low probability of exploitation in the next 30 days; routine patching cadence is appropriate. 62nd percentile — 62.2% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.

EPSS trend (30 days)EPSS over the last 30 days for CVE-2023-20027: held from 0.010 to 0.010.

EPSS over last 30 days · oldest: 0.010 · newest: 0.010 · change: 0.000

Affected products

Weakness classification (CWE)

References

Frequently asked questions

What is CVE-2023-20027?
CVE-2023-20027 is a high-severity vulnerability in Cisco 1000 Integrated Services Router, classified under Use After Free. CVSS score: 8.6/10. Published 2023-03-23.
How severe is CVE-2023-20027?
High severity. CVSS v3 base score is 8.6 out of 10.