CVE-2012-3406: Stack overflow in vfprintf [BZ #16617]

A larger number of format specifiers coudld cause a stack overflow,
potentially allowing to bypass _FORTIFY_SOURCE format string
protection.

(cherry picked from commit a5357b7ce2a2982c5778435704bcdb55ce3667a0)
(cherry picked from commit ae61fc7b33d9d99d2763c16de8275227dc9748ba)

Conflicts:
	NEWS