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
EPSS: 0.010 (60.5th percentile) — read the EPSS interpretation.
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.
Affected products
- Cisco 1000_integrated_services_router
- Cisco 1100-4g\/6g_integrated_services_router
- Cisco 1100-4g_integrated_services_router
- Cisco 1100-4p_integrated_services_router
- Cisco 1100-6g_integrated_services_router
- Cisco 1100-8p_integrated_services_router
- Cisco 1100_integrated_services_router
- Cisco 1101-4p_integrated_services_router
- Cisco 1101_integrated_services_router
- Cisco 1109-2p_integrated_services_router
Weakness classification (CWE)
References
- psirt@cisco.com (vendor-advisory, Vendor Advisory)
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.