codefromthe70s.org
I can't stress enough how important it is to have this blacklist installed. Detailed description of the issue is available both on the plug-in page and at this URL:
http://www.metasploit.com/users/hdm/tools/debian-openssl
This is a Firefox plug-in that checks SSL certificates against the list of the RSA keys compromised by Debian's predictable OpenSSL PRNG mess. A site using such certificates appears completely normal and secure in the Firefox. However it is absolutely trivial to mount a man-in-the-middle attack against an SSL session with such a site, thus completely negating the effects of SSL protection.
Detailed description of the issue is available both on the plug-in page and at this URL:
http://www.metasploit.com/users/hdm/tools/debian-openssl
(edit)
Here is a notable example - https://www.clickpass.com
For one thing, in path attacks not on the local network are more or less impossible. Even if you're talking to a server which has a weak key, the chances that your data will be compromised is small.
Second, nowhere that collects important details is going to have a weak key. This is Debian we're talking about. This is not a distribution that is used by a many online retailers. Even if it was, anywhere you're likely to trust is going to be using TLS offload cards anyway, which have hardware secure random number generators.
Third, anywhere you'd trust with important personal details has already reacted and generated new keys. If the people you're dealing with aren't keeping up with high publicity security advisories sure as hell aren't keeping up with much lower profile advisories. This will tend to mean you are far more at risk from the server itself being compromised, rather than any communication in progress.