screen - security update

A vulnerability was found in screen causing a stack overflow which
results in crashing the screen server process, resulting in denial
of service.

For the oldstable distribution (wheezy), this problem has been fixed
in version 4.1.0~20120320gitdb59704-7+deb7u1.

For the stable distribution (jessie), this problem has been fixed in
version 4.2.1-3+deb8u1.

For the testing (stretch) and unstable (sid) distributions, this problem
has been fixed in version 4.3.1-2.

We recommend that you upgrade your screen packages.