{"id":"CVE-2018-15443","aliases":["EUVD-2018-7321","GHSA-r3fv-hxw4-7fj4"],"status":"published","title":"Cisco Firepower Detection Engine TCP Intrusion Prevention System Rule Bypass Vulnerability","description":"A vulnerability in the detection engine of Cisco Firepower System Software could allow an unauthenticated, remote attacker to bypass a configured Intrusion Prevention System (IPS) rule that inspects certain types of TCP traffic. The vulnerability is due to incorrect TCP retransmission handling. An attacker could exploit this vulnerability by sending a crafted TCP connection request through an affected device. A successful exploit could allow the attacker to bypass configured IPS rules and allow uninspected traffic onto the network.","severity":{"version":"3.0","score":5.8,"vector":"CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N","level":"medium","assessor":"cna","from":"cve"},"epss":{"day":"2026-11-08","score":0.02767,"percentile":0.86403,"model":"v2026.06.15"},"facts":{"in_kev":false,"known_exploited":false,"public_exploit":false,"fix_available":false},"cwes":["CWE-400"],"published":"2018-11-08T17:00:00Z","modified":"2026-06-17T01:42:30Z","products":[{"vendor":"cisco","product":"cisco firepower management center"},{"vendor":"cisco","product":"firepower_system_software"}],"references":[{"url":"https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20181107-fde-tcp-bypass","tags":["vendor-advisory","x_refsource_CISCO","x_transferred","Vendor Advisory"]},{"url":"http://www.securityfocus.com/bid/105870","tags":["vdb-entry","x_refsource_BID","x_transferred","Third Party Advisory","VDB Entry"]},{"url":"https://nvd.nist.gov/vuln/detail/CVE-2018-15443"},{"url":"https://github.com/advisories/GHSA-r3fv-hxw4-7fj4"}],"sources":{"cve":[{"id":"CVE-2018-15443","title":"Cisco Firepower Detection Engine TCP Intrusion Prevention System Rule Bypass Vulnerability","description":"A vulnerability in the detection engine of Cisco Firepower System Software could allow an unauthenticated, remote attacker to bypass a configured Intrusion Prevention System (IPS) rule that inspects certain types of TCP traffic. The vulnerability is due to incorrect TCP retransmission handling. An attacker could exploit this vulnerability by sending a crafted TCP connection request through an affected device. A successful exploit could allow the attacker to bypass configured IPS rules and allow uninspected traffic onto the network.","status":"published","published":"2018-11-08T17:00:00Z","modified":"2024-11-26T14:22:11.255Z","cvss":[{"version":"3.0","score":5.8,"vector":"CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N","level":"medium","assessor":"cna"}],"cwes":["CWE-400"],"updated_at":"2026-11-02T14:35:03.825765Z"}],"euvd":[{"id":"EUVD-2018-7321","description":"A vulnerability in the detection engine of Cisco Firepower System Software could allow an unauthenticated, remote attacker to bypass a configured Intrusion Prevention System (IPS) rule that inspects certain types of TCP traffic. The vulnerability is due to incorrect TCP retransmission handling. An attacker could exploit this vulnerability by sending a crafted TCP connection request through an affected device. A successful exploit could allow the attacker to bypass configured IPS rules and allow uninspected traffic onto the network.","status":"published","published":"2018-11-08T17:00:00Z","modified":"2024-11-26T14:22:11Z","cvss":[{"version":"3.0","score":5.8,"vector":"CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N","level":"medium"}],"updated_at":"2026-11-03T00:04:47.994843Z"}],"ghsa":[{"id":"GHSA-r3fv-hxw4-7fj4","title":"A vulnerability in the detection engine of Cisco Firepower System Software could allow an...","description":"A vulnerability in the detection engine of Cisco Firepower System Software could allow an unauthenticated, remote attacker to bypass a configured Intrusion Prevention System (IPS) rule that inspects certain types of TCP traffic. The vulnerability is due to incorrect TCP retransmission handling. An attacker could exploit this vulnerability by sending a crafted TCP connection request through an affected device. A successful exploit could allow the attacker to bypass configured IPS rules and allow uninspected traffic onto the network.","status":"published","published":"2022-05-13T01:34:16Z","modified":"2023-02-01T05:08:41Z","cvss":[{"version":"3.0","score":7.5,"vector":"CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N","level":"high"}],"cwes":["CWE-400"],"updated_at":"2026-11-02T14:50:49.963472Z"}],"nvd":[{"id":"CVE-2018-15443","description":"A vulnerability in the detection engine of Cisco Firepower System Software could allow an unauthenticated, remote attacker to bypass a configured Intrusion Prevention System (IPS) rule that inspects certain types of TCP traffic. The vulnerability is due to incorrect TCP retransmission handling. An attacker could exploit this vulnerability by sending a crafted TCP connection request through an affected device. A successful exploit could allow the attacker to bypass configured IPS rules and allow uninspected traffic onto the network.","status":"published","published":"2018-11-08T17:29:00.653Z","modified":"2026-06-17T01:42:30.45Z","cvss":[{"version":"3.0","score":5.8,"vector":"CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:C/C:N/I:L/A:N","level":"medium","assessor":"secondary"},{"version":"3.0","score":7.5,"vector":"CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:H/A:N","level":"high","assessor":"primary"},{"version":"2.0","score":5,"vector":"AV:N/AC:L/Au:N/C:N/I:P/A:N","level":"medium","assessor":"primary"}],"cwes":["CWE-400"],"updated_at":"2026-11-02T14:04:47.196456Z"}]}}