{"id":"CVE-2015-1637","url":"https://www.cyber-defence.io/tools/cve/CVE-2015-1637","generatedAt":"2026-11-05T06:27:58.978Z","title":"Schannel (aka Secure Channel) in Microsoft Windows Server 2003 SP2, Windows Vista SP2, Windows Server 2008 SP2 and R2 SP1, Windows 7 SP1, Windows 8, Windows 8.1, Windows Server 2012 Gold and R2, and Windows RT Gold and 8.1 does not properly restrict TLS…","description":"Schannel (aka Secure Channel) in Microsoft Windows Server 2003 SP2, Windows Vista SP2, Windows Server 2008 SP2 and R2 SP1, Windows 7 SP1, Windows 8, Windows 8.1, Windows Server 2012 Gold and R2, and Windows RT Gold and 8.1 does not properly restrict TLS state transitions, which makes it easier for remote attackers to conduct cipher-downgrade attacks to EXPORT_RSA ciphers via crafted TLS traffic, related to the \"FREAK\" issue, a different vulnerability than CVE-2015-0204 and CVE-2015-1067.","published":"2015-03-06T17:59:00.000Z","lastModified":"2026-06-17T00:22:45.000Z","status":"Modified","sourceIdentifier":"secure@microsoft.com","cvss":{"version":"2.0","score":4.3,"severity":"MEDIUM","vector":"AV:N/AC:M/Au:N/C:N/I:P/A:N"},"cwe":["CWE-310"],"affected":["microsoft/windows 7","microsoft/windows 8","microsoft/windows 8.1","microsoft/windows rt","microsoft/windows rt 8.1","microsoft/windows server 2003","microsoft/windows server 2008","microsoft/windows server 2012","microsoft/windows vista"],"epss":{"score":0.13151,"percentile":0.96373,"date":"2026-11-04","history":[]},"kev":{"listed":false},"exploits":{"count":0,"verified":false,"firstPublished":null,"source":"Exploit-DB (https://gitlab.com/exploit-database/exploitdb)","entries":[]},"verdict":{"level":"urgent","text":"EPSS puts the probability of exploitation in the next 30 days at 13.2%, higher than 96% of all known CVEs. Patch or mitigate before the next change window."},"changes":[],"references":[{"url":"http://web.archive.org/web/20150321220028/https://freakattack.com/","source":"secure@microsoft.com"},{"url":"http://www.securityfocus.com/bid/72965","tags":["Third Party Advisory","VDB Entry"],"source":"secure@microsoft.com"},{"url":"http://www.securitytracker.com/id/1031833","tags":["Third Party Advisory","VDB Entry"],"source":"secure@microsoft.com"},{"url":"https://docs.microsoft.com/en-us/security-updates/securitybulletins/2015/ms15-031","tags":["Patch","Vendor Advisory"],"source":"secure@microsoft.com"},{"url":"https://freakattack.com/","tags":["Vendor Advisory"],"source":"secure@microsoft.com"},{"url":"https://technet.microsoft.com/library/security/3046015","tags":["Patch","Vendor Advisory"],"source":"secure@microsoft.com"},{"url":"http://web.archive.org/web/20150321220028/https://freakattack.com/","source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"http://www.securityfocus.com/bid/72965","tags":["Third Party Advisory","VDB Entry"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"http://www.securitytracker.com/id/1031833","tags":["Third Party Advisory","VDB Entry"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://docs.microsoft.com/en-us/security-updates/securitybulletins/2015/ms15-031","tags":["Patch","Vendor Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://freakattack.com/","tags":["Vendor Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"},{"url":"https://technet.microsoft.com/library/security/3046015","tags":["Patch","Vendor Advisory"],"source":"af854a3a-2127-422b-91ae-364da2661108"}],"sources":{"nvd":"https://nvd.nist.gov/vuln/detail/CVE-2015-1637","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."}