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CVE-2015-1637

Schannel (aka Secure Channel) in Microsoft Windows Server 2003 SP2, Windows Vista SP2, Windows...

4.3 Medium

CVE-2015-1637 is a medium vulnerability (CVSS 4.3) in Microsoft Windows 7, published March 6, 2015. No source lists public exploit code. EPSS puts the chance of exploitation in the next 30 days at 13.2%, the 96th percentile. No source names a fixed version.

What does this mean?
Severity
4.3 MediumCVSS 2.0, NVD
Exploit chance
13.2%EPSS, 96th percentile
Exploitation
None knownNot on CISA’s or ENISA’s lists
Fixed in
No fix listedNo source names one

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.

Exploit likelihood

13.2%Down 16.4 points since Feb 4, 2022
90%50%10%1%

Affected products

What each source reports

NVD Score used4.3

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.

Record
CVE-2015-1637
CVSS 2.0
4.3 MediumAV:N/AC:M/Au:N/C:N/I:P/A:N
Weakness
CWE-310
Updated
2026-11-02
CVE ListNo score

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.

Record
CVE-2015-1637
Updated
2026-11-02
EUVDEUVD-2015-1767No score

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.

Record
EUVD-2015-1767
Updated
2026-11-03
GitHub AdvisoriesGHSA-h5m2-xvgx-vpw7No score

Schannel (aka Secure Channel) in Microsoft Windows Server 2003 SP2, Windows Vista SP2, Windows...

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.

Record
GHSA-h5m2-xvgx-vpw7
Updated
2026-11-02

History

History
RecordedChangedSources
facts
aliasesEUVD
first indexedCVE List, GitHub Advisories, NVD

Dates are when Every CVE recorded each change. Upstream dates may differ.

References

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