{"id":"CVE-2017-6030","url":"https://www.cyber-defence.io/tools/cve/CVE-2017-6030","generatedAt":"2026-10-28T20:49:18.624Z","title":"The affected products generate insufficiently random TCP initial sequence numbers that may allow an attacker to predict the numbers from previous values.","description":"A predictable value range from previous values issue was discovered in Schneider Electric Modicon PLCs Modicon M221, firmware versions prior to Version 1.5.0.0, Modicon M241, firmware versions prior to Version 4.0.5.11, and Modicon M251, firmware versions prior to Version 4.0.5.11. The affected products generate insufficiently random TCP initial sequence numbers that may allow an attacker to predict the numbers from previous values. This may allow an attacker to spoof or disrupt TCP connections.","published":"2017-06-30T03:29:00.000Z","lastModified":"2026-06-17T01:21:40.000Z","status":"Modified","sourceIdentifier":"ics-cert@hq.dhs.gov","cvss":{"version":"3.1","score":6.5,"severity":"MEDIUM","vector":"CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:L/A:L"},"cwe":["CWE-343","CWE-331"],"affected":["schneider-electric/modicon m241 firmware","schneider-electric/modicon m251 firmware","schneider-electric/modicon m221 firmware"],"epss":{"score":0.02184,"percentile":0.8229,"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 (2.18%). Track it; it rarely justifies an emergency change on its own."},"changes":[],"references":[{"url":"http://www.securityfocus.com/bid/97254","tags":["Third Party Advisory","VDB Entry"],"source":"ics-cert@hq.dhs.gov"},{"url":"https://github.com/cisagov/CSAF/blob/develop/csaf_files/OT/white/2017/icsa-17-089-02.json","source":"ics-cert@hq.dhs.gov"},{"url":"https://ics-cert.us-cert.gov/advisories/ICSA-17-089-02","tags":["Third Party Advisory","US Government Resource"],"source":"ics-cert@hq.dhs.gov"},{"url":"http://www.securityfocus.com/bid/97254","tags":["Third Party Advisory","VDB Entry"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://ics-cert.us-cert.gov/advisories/ICSA-17-089-02","tags":["Third Party Advisory","US Government Resource"],"source":"af854a3a-2127-422b-91ae-364da2661108"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2017-6030","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."}