I believe that cursor flash is a character attribute that is sent with
the original stream, kind of like bold or underline. It is NOT a
continuous data flow. I believe the security exploit was looking for
more than just a few characters within a packet to be repeated, I
think they were looking for a small but repeated packet with a "fixed"
phrase.

If you check the most recent versions of Firefox, and possibly other
browsers, you will find that SSLv3 has been disabled and only the TLS
protocols are now allowed. That is because there was a bug in the
SSLv3 protocol such that it was using a bad algorithm and could be
compromised. See Episode 478 "Poodle Bites" and more in episode 485.

I don't remember the full details of the SSLv3 problem, but I
regularly find that the Security Now podcast tends to give the most
complete and in depth explanations of what is happening in computer
security. They tend to be much more in-depth and geeky propeller head
level than the other podcasts I've listened to. If you want the
de-hyped in-depth version of the latest security holes, this is a good
place to look. I'm listening to the latest podcast now to find out
what the Turla backdoor for Linux is....
https://www.grc.com/securitynow.htm

I believe Steve Gibson and Security Now was mentioned in this remailer
some time ago, and a number of people had negative comments about him.
Personally I enjoy his style and have no reason to believe his
explanation of the security problems isn't accurate. I remember
reading his columns back in the 80's and enjoyed his writing.

Doug.