{"id":"CVE-2023-20072","aliases":["EUVD-2023-24251","GHSA-57j4-jv54-9h84"],"status":"published","title":"Cisco IOS XE Software Fragmented Tunnel Protocol Packet Denial of Service Vulnerability","description":"A vulnerability in the fragmentation handling code of tunnel protocol packets in Cisco IOS XE Software could allow an unauthenticated, remote attacker to cause an affected system to reload, resulting in a denial of service (DoS) condition. This vulnerability is due to the improper handling of large fragmented tunnel protocol packets. One example of a tunnel protocol is Generic Routing Encapsulation (GRE). An attacker could exploit this vulnerability by sending crafted fragmented packets to an affected system. A successful exploit could allow the attacker to cause the affected system to reload, resulting in a DoS condition. Note: Only traffic directed to the affected system can be used to exploit this vulnerability.","severity":{"version":"3.1","score":8.6,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H","level":"high","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-11","score":0.0098,"percentile":0.62656,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-20"],"published":"2023-03-23T00:00:00Z","modified":"2026-06-17T05:29:24Z","products":[{"vendor":"cisco","product":"cisco ios xe software"},{"vendor":"cisco","product":"ios_xe"}],"references":[{"url":"https://sec.cloudapps.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-ios-gre-crash-p6nE5Sq5","tags":["vendor-advisory","x_transferred","Vendor Advisory"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2023-20072"},{"url":"https://github.com/advisories/GHSA-57j4-jv54-9h84"}],"sources":{"cve":[{"id":"CVE-2023-20072","title":"Cisco IOS XE Software Fragmented Tunnel Protocol Packet Denial of Service Vulnerability","description":"A vulnerability in the fragmentation handling code of tunnel protocol packets in Cisco IOS XE Software could allow an unauthenticated, remote attacker to cause an affected system to reload, resulting in a denial of service (DoS) condition. This vulnerability is due to the improper handling of large fragmented tunnel protocol packets. One example of a tunnel protocol is Generic Routing Encapsulation (GRE). An attacker could exploit this vulnerability by sending crafted fragmented packets to an affected system. A successful exploit could allow the attacker to cause the affected system to reload, resulting in a DoS condition. Note: Only traffic directed to the affected system can be used to exploit this vulnerability.","status":"published","published":"2023-03-23T00:00:00Z","modified":"2024-10-28T16:32:38.86Z","cvss":[{"version":"3.1","score":8.6,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H","level":"high","assessor":"cna"}],"cwes":["CWE-20"],"updated_at":"2026-11-02T14:35:13.368958Z"}],"euvd":[{"id":"EUVD-2023-24251","description":"A vulnerability in the fragmentation handling code of tunnel protocol packets in Cisco IOS XE Software could allow an unauthenticated, remote attacker to cause an affected system to reload, resulting in a denial of service (DoS) condition. This vulnerability is due to the improper handling of large fragmented tunnel protocol packets. One example of a tunnel protocol is Generic Routing Encapsulation (GRE). An attacker could exploit this vulnerability by sending crafted fragmented packets to an affected system. A successful exploit could allow the attacker to cause the affected system to reload, resulting in a DoS condition. Note: Only traffic directed to the affected system can be used to exploit this vulnerability.","status":"published","published":"2023-03-23T00:00:00Z","modified":"2024-10-28T16:32:38Z","cvss":[{"version":"3.1","score":8.6,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H","level":"high"}],"updated_at":"2026-11-03T00:05:16.135425Z"}],"ghsa":[{"id":"GHSA-57j4-jv54-9h84","title":"A vulnerability in the fragmentation handling code of tunnel protocol packets in Cisco IOS XE...","description":"A vulnerability in the fragmentation handling code of tunnel protocol packets in Cisco IOS XE Software could allow an unauthenticated, remote attacker to cause an affected system to reload, resulting in a denial of service (DoS) condition. This vulnerability is due to the improper handling of large fragmented tunnel protocol packets. One example of a tunnel protocol is Generic Routing Encapsulation (GRE). An attacker could exploit this vulnerability by sending crafted fragmented packets to an affected system. A successful exploit could allow the attacker to cause the affected system to reload, resulting in a DoS condition. Note: Only traffic directed to the affected system can be used to exploit this vulnerability.","status":"published","published":"2023-03-23T18:30:19Z","modified":"2023-04-08T05:00:55Z","cvss":[{"version":"3.1","score":8.6,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H","level":"high"}],"updated_at":"2026-11-02T14:54:27.812339Z"}],"nvd":[{"id":"CVE-2023-20072","description":"A vulnerability in the fragmentation handling code of tunnel protocol packets in Cisco IOS XE Software could allow an unauthenticated, remote attacker to cause an affected system to reload, resulting in a denial of service (DoS) condition. This vulnerability is due to the improper handling of large fragmented tunnel protocol packets. One example of a tunnel protocol is Generic Routing Encapsulation (GRE). An attacker could exploit this vulnerability by sending crafted fragmented packets to an affected system. A successful exploit could allow the attacker to cause the affected system to reload, resulting in a DoS condition. Note: Only traffic directed to the affected system can be used to exploit this vulnerability.","status":"published","published":"2023-03-23T17:15:14.727Z","modified":"2026-06-17T05:29:24.84Z","cvss":[{"version":"3.1","score":8.6,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H","level":"high","assessor":"secondary"},{"version":"3.1","score":8.6,"vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:N/A:H","level":"high","assessor":"primary"}],"cwes":["CWE-20"],"updated_at":"2026-11-02T14:07:50.908252Z"}]}}