claws-mail - security update

“DrWhax” of the Tails project reported that Claws Mail is missing
range checks in some text conversion functions. A remote attacker
could exploit this to run arbitrary code under the account of a user
that receives a message from them using Claws Mail.

• CVE-2015-8614
  There were no checks on the output length for conversions between
  JIS (ISO-2022-JP) and EUC-JP, between JIS and UTF-8, and from
  Shift_JIS to EUC-JP.
• CVE-2015-8708
  The original fix for CVE-2015-8614 was incomplete.

For the oldoldstable distribution (squeeze), these problems have been
fixed in version 3.7.6-4+squeeze2.

For the oldstable distribution (wheezy) and the stable distribution
(jessie), this will be fixed soon. These versions were built with
hardening features that make this issue harder to exploit.