{"id":"CVE-2018-5389","url":"https://www.cyber-defence.io/tools/cve/CVE-2018-5389","generatedAt":"2026-10-28T21:31:12.208Z","title":"The Internet Key Exchange v1 main mode is vulnerable to offline dictionary or brute force attacks.","description":"The Internet Key Exchange v1 main mode is vulnerable to offline dictionary or brute force attacks. Reusing a key pair across different versions and modes of IKE could lead to cross-protocol authentication bypasses. It is well known, that the aggressive mode of IKEv1 PSK is vulnerable to offline dictionary or brute force attacks. For the main mode, however, only an online attack against PSK authentication was thought to be feasible. This vulnerability could allow an attacker to recover a weak Pre-Shared Key or enable the impersonation of a victim host or network.","published":"2018-09-06T21:29:00.000Z","lastModified":"2026-06-17T02:00:15.000Z","status":"Modified","sourceIdentifier":"cret@cert.org","cvss":{"version":"3.0","score":5.9,"severity":"MEDIUM","vector":"CVSS:3.0/AV:N/AC:H/PR:N/UI:N/S:U/C:H/I:N/A:N"},"cwe":["CWE-521"],"affected":["ietf/internet key exchange"],"epss":{"score":0.03064,"percentile":0.8755,"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 (3.06%). Track it; it rarely justifies an emergency change on its own."},"changes":[],"references":[{"url":"https://blogs.cisco.com/security/great-cipher-but-where-did-you-get-that-key","tags":["Third Party Advisory"],"source":"cret@cert.org"},{"url":"https://my.f5.com/manage/s/article/K42378447","source":"cret@cert.org"},{"url":"https://web-in-security.blogspot.com/2018/08/practical-dictionary-attack-on-ipsec-ike.html","tags":["Exploit","Third Party Advisory"],"source":"cret@cert.org"},{"url":"https://www.kb.cert.org/vuls/id/857035","tags":["Third Party Advisory","US Government Resource"],"source":"cret@cert.org"},{"url":"https://www.usenix.org/system/files/conference/usenixsecurity18/sec18-felsch.pdf","tags":["Third Party Advisory"],"source":"cret@cert.org"},{"url":"https://blogs.cisco.com/security/great-cipher-but-where-did-you-get-that-key","tags":["Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://my.f5.com/manage/s/article/K42378447","source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://web-in-security.blogspot.com/2018/08/practical-dictionary-attack-on-ipsec-ike.html","tags":["Exploit","Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://www.kb.cert.org/vuls/id/857035","tags":["Third Party Advisory","US Government Resource"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://www.usenix.org/system/files/conference/usenixsecurity18/sec18-felsch.pdf","tags":["Third Party Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2018-5389","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."}