Getting SSL_ERROR_ILLEGAL_PARAMETER_ALERT for urls with underscore.

[Abhay Gupta]

Hi team,

I am trying to inspect a website which on load makes ajax calls to API on it's subdomain.

There's an underscore in the subdomain. e.g. api_1.target.com I am using ZAP Proxy's browser.

The API call fails with SSL_ERROR_ILLEGAL_PARAMETER_ALERT when ZAP proxy is on. The issue was same for both chrome & firefox.

There's same issue with Burp community edition. (https://forum.portswigger.net/thread/ssl-error-illegal-parameter-alert-28b0fc61)

Can anyone help me with a work around for this? Sorry can't name the original target website here.

[thc...@gmail.com]

Hi,

Not sure there's an easy workaround, the error is from the JDK
implementation.

Can you provide the whole stacktrace?

Best regards.