The (1) ssh2_load_userkey and (2) ssh2_save_userkey functions in PuTTY 0.51 through 0.63 do not properly wipe SSH-2 private keys from memory, which allows local users to obtain sensitive information by reading the memory.
http://www.securityfocus.com/bid/72825
http://www.openwall.com/lists/oss-security/2015/02/28/5
http://www.openwall.com/lists/oss-security/2015/02/28/4
http://www.debian.org/security/2015/dsa-3190
http://www.chiark.greenend.org.uk/~sgtatham/putty/wishlist/private-key-not-wiped-2.html
http://www.chiark.greenend.org.uk/~sgtatham/putty/changes.html
http://lists.opensuse.org/opensuse-updates/2015-03/msg00032.html
http://lists.fedoraproject.org/pipermail/package-announce/2015-March/151933.html
http://lists.fedoraproject.org/pipermail/package-announce/2015-March/151839.html
http://lists.fedoraproject.org/pipermail/package-announce/2015-March/151790.html