The SPDY protocol 3 and earlier, as used in Mozilla Firefox, Google Chrome, and other products, can perform TLS encryption of compressed data without properly obfuscating the length of the unencrypted data, which allows man-in-the-middle attackers to obtain plaintext HTTP headers by observing length differences during a series of guesses in which a string in an HTTP request potentially matches an unknown string in an HTTP header, aka a "CRIME" attack.
https://bugzilla.redhat.com/show_bug.cgi?id=857737
http://www.theregister.co.uk/2012/09/14/crime_tls_attack/
http://www.iacr.org/cryptodb/data/paper.php?pubkey=3091
http://www.ekoparty.org/2012/thai-duong.php
http://lists.opensuse.org/opensuse-security-announce/2012-10/msg00010.html
http://isecpartners.com/blog/2012/9/14/details-on-the-crime-attack.html
http://arstechnica.com/security/2012/09/crime-hijacks-https-sessions/