Você não precisa desativar o SSL3. Você pode ativar o SSL3 e ter o POODLE mitigado .
# Copy and paste this in PowerShell then restart your server
$cipherSuitesOrder = @(
'TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256',
'TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P384',
'TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA_P256',
'TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA_P384',
'TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA_P256',
'TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA_P384',
'TLS_RSA_WITH_AES_128_CBC_SHA256',
'TLS_RSA_WITH_AES_128_CBC_SHA',
'TLS_RSA_WITH_AES_256_CBC_SHA256',
'TLS_RSA_WITH_AES_256_CBC_SHA',
'TLS_RSA_WITH_RC4_128_SHA',
'TLS_RSA_WITH_3DES_EDE_CBC_SHA',
'TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256_P256',
'TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256_P256',
'TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384_P384',
'TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA384_P384',
'TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA_P256',
'TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA_P384',
'TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA_P256',
'TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA_P384'
)
$cipherSuitesAsString = [string]::join(',', $cipherSuitesOrder)
New-ItemProperty -path 'HKLM:\SOFTWARE\Policies\Microsoft\Cryptography\Configuration\SSL# Copy and paste this in PowerShell then restart your server
$cipherSuitesOrder = @(
'TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P256',
'TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256_P384',
'TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA_P256',
'TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA_P384',
'TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA_P256',
'TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA_P384',
'TLS_RSA_WITH_AES_128_CBC_SHA256',
'TLS_RSA_WITH_AES_128_CBC_SHA',
'TLS_RSA_WITH_AES_256_CBC_SHA256',
'TLS_RSA_WITH_AES_256_CBC_SHA',
'TLS_RSA_WITH_RC4_128_SHA',
'TLS_RSA_WITH_3DES_EDE_CBC_SHA',
'TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256_P256',
'TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256_P256',
'TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384_P384',
'TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA384_P384',
'TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA_P256',
'TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA_P384',
'TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA_P256',
'TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA_P384'
)
$cipherSuitesAsString = [string]::join(',', $cipherSuitesOrder)
New-ItemProperty -path 'HKLM:\SOFTWARE\Policies\Microsoft\Cryptography\Configuration\SSL%pre%010002' \
-name 'Functions' -value $cipherSuitesAsString -PropertyType 'String' -Force | Out-Null
010002' \
-name 'Functions' -value $cipherSuitesAsString -PropertyType 'String' -Force | Out-Null
Com essas configurações, você ainda teria suporte ao IE6 (com SSLv3 usando RC4) e teria uma segurança de configuração mais que aceitável. Apenas o IE6 e o cliente realmente antigo usariam as criptografias SSLv3 ou RC4.