Windows 11: unable to connect to SQL 2008 [Microsoft][ODBC SQL Server Driver][DBNETLIB]SSL Security error

 Suddenly this error appears on ODBC connections to legacy SQL 2008 servers.

Apparently, latest updates on Windows 11 (some Windows 10 reported too), "breaks" connections to SQL 2008.

Resolution

Update your Cipher Suite on Windows.

Since Windows 22H2, the default TLS Cipher Suites changed. 

The following were removed from the default:

 "TLS_DHE_RSA_WITH_AES_256_GCM_SHA384,TLS_DHE_RSA_WITH_AES_128_GCM_SHA256,TLS_RSA_WITH_3DES_EDE_CBC_SHA"

So I updated the SSL Cipher Suites on Windows 11 x64 (more information about this: https://support.microsoft.com/en-us/topic/update-to-add-new-cipher-suites-to-internet-explorer-and-microsoft-edge-in-windows-548427db-ed06-5521-fe8b-d525ab573022

The list I used was the one that was used for Windows prior to the 22H2 (22621.819) update (Please be advised that this response is to answer the question that was given and obviously does not follow best practice procedures. Microsoft disabled this encryption for a reason. If you are like me and have older servers that need to keep running while you come up with a long-term solution to discontinue them then the above solution will keep you operational.):

 TLS_AES_256_GCM_SHA384,TLS_AES_128_GCM_SHA256,TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384,TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256,TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384,TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256,TLS_DHE_RSA_WITH_AES_256_GCM_SHA384,TLS_DHE_RSA_WITH_AES_128_GCM_SHA256,TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA384,TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256,TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384,TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256,TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA,TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA,TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA,TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA,TLS_RSA_WITH_AES_256_GCM_SHA384,TLS_RSA_WITH_AES_128_GCM_SHA256,TLS_RSA_WITH_AES_256_CBC_SHA256,TLS_RSA_WITH_AES_128_CBC_SHA256,TLS_RSA_WITH_AES_256_CBC_SHA,TLS_RSA_WITH_AES_128_CBC_SHA,TLS_RSA_WITH_3DES_EDE_CBC_SHA,TLS_RSA_WITH_NULL_SHA256,TLS_RSA_WITH_NULL_SHA,TLS_PSK_WITH_AES_256_GCM_SHA384,TLS_PSK_WITH_AES_128_GCM_SHA256,TLS_PSK_WITH_AES_256_CBC_SHA384,TLS_PSK_WITH_AES_128_CBC_SHA256,TLS_PSK_WITH_NULL_SHA384,TLS_PSK_WITH_NULL_SHA256 

REG KEY FILE

You may use this to create a .REG file, load it on Windows 11:

Windows Registry Editor Version 5.00

[HKEY_LOCAL_MACHINE\SOFTWARE\Policies\Microsoft\Cryptography\Configuration\SSL\00010002]

"Functions"="TLS_AES_256_GCM_SHA384,TLS_AES_128_GCM_SHA256,TLS_ECDHE_ECDSA_WITH_AES_256_GCM_SHA384,TLS_ECDHE_ECDSA_WITH_AES_128_GCM_SHA256,TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384,TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256,TLS_DHE_RSA_WITH_AES_256_GCM_SHA384,TLS_DHE_RSA_WITH_AES_128_GCM_SHA256,TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA384,TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA256,TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA384,TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA256,TLS_ECDHE_ECDSA_WITH_AES_256_CBC_SHA,TLS_ECDHE_ECDSA_WITH_AES_128_CBC_SHA,TLS_ECDHE_RSA_WITH_AES_256_CBC_SHA,TLS_ECDHE_RSA_WITH_AES_128_CBC_SHA,TLS_RSA_WITH_AES_256_GCM_SHA384,TLS_RSA_WITH_AES_128_GCM_SHA256,TLS_RSA_WITH_AES_256_CBC_SHA256,TLS_RSA_WITH_AES_128_CBC_SHA256,TLS_RSA_WITH_AES_256_CBC_SHA,TLS_RSA_WITH_AES_128_CBC_SHA,TLS_RSA_WITH_3DES_EDE_CBC_SHA,TLS_RSA_WITH_NULL_SHA256,TLS_RSA_WITH_NULL_SHA,TLS_PSK_WITH_AES_256_GCM_SHA384,TLS_PSK_WITH_AES_128_GCM_SHA256,TLS_PSK_WITH_AES_256_CBC_SHA384,TLS_PSK_WITH_AES_128_CBC_SHA256"

Restart Windows to apply changes.