Issue
When browsing to SecurityScorecard Platform https://platform.securityscorecard.io, the following error occurs and the platform cannot be accessed:
ERR_SSL_VERSION_OR_CIPHER_MISMATCH
Answer
This error occurs as the web browser fails to establish a secure connection using a supported TLS/SSL protocol and cipher suite during the handshake.
On Jan 30, 2025, the cipher suite supported by platform.securityscorecard.io was updated from TLSv1.2_2018 to TLSv1.2_2021, dropping support for the following ciphers:
ECDHE-ECDSA-AES128-SHA256
ECDHE-ECDSA-AES256-SHA384
ECDHE-RSA-AES128-SHA256
ECDHE-RSA-AES256-SHA384
AES128-GCM-SHA256
AES256-GCM-SHA384
AES128-SHA256
In order to continue using the SecurityScorecard Platform, please use an up-to-date browser that supports the secure ciphers from the TLSv1.2_2021 suite. Don't hesitate to consult your IT team for support, review browser configurations and update your web browser.
See Also
AWS Cloudfront article about cipher details:
https://docs.aws.amazon.com/AmazonCloudFront/latest/DeveloperGuide/secure-connections-supported-viewer-protocols-ciphers.html