HELO command in Sendmail allows a remote attacker to hide activities. NIST National Vulnerability Database (NVD) -- services.nvd.nist.gov (CVE / CVSS / CPE). {"cve":{"id":"CVE-1999-0098","sourceIdentifier":"cve@mitre.org","published":"1998-04-01T05:00:00.000","lastModified":"2026-06-16T21:47:34.903","vulnStatus":"Modified","cveTags":[],"descriptions":[{"lang":"en","value":"Buffer overflow in SMTP HELO command in Sendmail allows a remote attacker to hide activities."}],"affected":[{"source":"cve@mitre.org","affectedData":[{"vendor":"n/a","product":"n/a","versions":[{"version":"n/a","status":"affected"}]}]}],"metrics":{"cvssMetricV2":[{"source":"nvd@nist.gov","type":"Primary","cvssData":{"version":"2.0","vectorString":"AV:N/AC:L/Au:N/C:C/I:C/A:C","baseScore":10.0,"accessVector":"NETWORK","accessComplexity":"LOW","authentication":"NONE","confidentialityImpact":"COMPLETE","integrityImpact":"COMPLETE","availabilityImpact":"COMPLETE"},"baseSeverity":"HIGH","exploitabilityScore":10.0,"impactScore":10.0,"acInsufInfo":false,"obtainAllPrivilege":true,"obtainUserPrivilege":false,"obtainOtherPrivilege":false,"userInteractionRequired":false}]},"weaknesses":[{"source":"nvd@nist.gov","type":"Primary","description":[{"lang":"en","value":"NVD-CWE-Other"}]}],"configurations":[{"nodes":[{"operator":"OR","negate":false,"cpeMatch":[{"vulnerable":true,"criteria":"cpe:2.3:a:apple:appleshare:-:*:*:ja:*:*:*:*","matchCriteriaId":"AB3E4751-4BC6-427E-BA98-6CD414D38AE1"},{"vulnerable":true,"criteria":"cpe:2.3:a:pmail:mercury_mail_server:-:*:*:*:*:*:*:*","matchCriteriaId":"DF801926-9C57-4BB9-A55A-FC35E86623B2"},{"vulnerable":true,"criteria":"cpe:2.3:a:seattlelab:slmail:2.6:*:*:*:*:*:*:*","matchCriteriaId":"65AE12AD-FD84-47F2-B8DB-B147EBC0C94B"}]}]}],"references":[{"url":"https://exchange.xforce.ibmcloud.com/vulnerabilities/CVE-1999-0098","source":"cve@mitre.org"},{"url":"https://exchange.xforce.ibmcloud.com/vulnerabilities/CVE-1999-0098","source":"af854a3a-2127-422b-91ae-364da2661108"}]}},