RFC 5246, "The Transport Layer Security (TLS) Protocol Version 1.2", August 2008

Note: This RFC has been obsoleted by RFC 8446

Errata ID: 4007
Status: Held for Document Update
Type: Technical
Publication Format(s) : TEXT
Reported By: KIKUCHI Masashi
Date Reported: 2014-06-06
Held for Document Update by: Stephen Farrell
Date Held: 2015-03-24

Section 7.3. says:

Note: To help avoid pipeline stalls, ChangeCipherSpec is an
   independent TLS protocol content type, and is not actually a TLS
   handshake message.

It should say:

Note: To avoid ChangeCipherSpec being transmitted in mix with
   other handshake fragments in one record, ChangeCipherSpec is
   an independent TLS protocol content type, and is not actually
   a TLS handshake message.  To help avoid pipeline stalls, 
   ChangeCipherSpec is sent from both the server and the client.

Notes:

The original text can be read like we can handle ChangeCipherSpec asynchronously.
This is harmful and may be a cause of CCS Injection vulnerability.

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