{"id":"CVE-2018-0447","url":"https://www.cyber-defence.io/tools/cve/CVE-2018-0447","generatedAt":"2026-10-28T20:08:50.193Z","title":"A vulnerability in the anti-spam protection mechanisms of Cisco AsyncOS Software for the Cisco Email Security Appliance (ESA) could allow an unauthenticated, remote attacker to bypass certain content filters on an affected device.","description":"A vulnerability in the anti-spam protection mechanisms of Cisco AsyncOS Software for the Cisco Email Security Appliance (ESA) could allow an unauthenticated, remote attacker to bypass certain content filters on an affected device. The vulnerability is due to incomplete input and validation checking mechanisms for certain Sender Policy Framework (SPF) messages that are sent to an affected device. An attacker could exploit this vulnerability by sending a customized SPF packet to an affected device. If successful, an exploit could allow the attacker to bypass the URL filters that are configured for the affected device, which could allow malicious URLs to pass through the device.","published":"2018-10-05T14:29:03.000Z","lastModified":"2026-06-17T01:30:50.000Z","status":"Modified","sourceIdentifier":"psirt@cisco.com","cvss":{"version":"3.0","score":5.3,"severity":"MEDIUM","vector":"CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:N"},"cwe":["CWE-284","CWE-20"],"affected":["cisco/email security appliance"],"epss":{"score":0.02276,"percentile":0.83006,"date":"2026-10-27","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"low","text":"Lower severity and a low EPSS score (2.28%). Track it; it rarely justifies an emergency change on its own."},"changes":[],"references":[{"url":"http://www.securityfocus.com/bid/105300","tags":["Third Party Advisory","VDB Entry"],"source":"psirt@cisco.com"},{"url":"http://www.securitytracker.com/id/1041687","tags":["Third Party Advisory","VDB Entry"],"source":"psirt@cisco.com"},{"url":"https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20180905-esa-url-bypass","tags":["Vendor Advisory"],"source":"psirt@cisco.com"},{"url":"http://www.securityfocus.com/bid/105300","tags":["Third Party Advisory","VDB Entry"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"http://www.securitytracker.com/id/1041687","tags":["Third Party Advisory","VDB Entry"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://tools.cisco.com/security/center/content/CiscoSecurityAdvisory/cisco-sa-20180905-esa-url-bypass","tags":["Vendor Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2018-0447","epss":"https://www.first.org/epss/","kev":"https://www.cisa.gov/known-exploited-vulnerabilities-catalog","exploitdb":"https://www.exploit-db.com/"},"licence":"CC BY 4.0 — link back to the CVE Explorer if you publish the results; upstream data remains subject to its own terms."}