On IIS, how do I patch the SSL 3.0 POODLE vulnerability (CVE­-2014­-3566)?

There is no “patch”. It’s a vulnerability in the protocol, not a bug in the implementation.

In Windows Server 2003 to 2012 R2 the SSL / TLS protocols are controlled by flags in the registry set at HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\SecurityProviders\Schannel\Protocols.

To disable SSLv3, which the POODLE vulnerability is concerned with, create a subkey at the above location (if it’s not already present) named SSL 3.0 and, under that, a subkey named Server (if it’s not already present). At this location (HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\SecurityProviders\Schannel\Protocols\SSL 3.0\Server) create a DWORD value named Enabled and leave it set at 0.

Disabling SSL 2.0, which you should also be doing, is done the same way, except that you’ll be using a key named SSL 2.0 in the above registry path.

I haven’t tested all versions, but I think it’s probably safe to assume that a reboot is necessary for this change to take effect.

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