Checks for GHOST vulnerability - See https://bugzilla.redhat.com/show_bug.cgi?id=CVE-2015-0235 AND http://people.canonical.com/~ubuntu-security/cve/2015/CVE-2015-0235.html FOR MORE DETAILS ON AFFECTED VERSIONS

DEBIAN_GHOST_CHECKER.sh

#!/bin/bash

## Thanks to https://gist.github.com/xurizaemon for sorting this version out for me! :)

DEB_OR_UBU=$(lsb_release -ds | cut -d " " -f 1)
INSTALLED_VERSION=$(dpkg -s libc6 | grep Version | awk '{ print $2 }')
FIXED_VERSION=""
if [ "$DEB_OR_UBU" == "Ubuntu" ]; then
  UBUNTU_RELEASE=$(lsb_release -sr | cut -d '.' -f 1)
  case $UBUNTU_RELEASE in
    10)
      FIXED_VERSION=2.11.1-0ubuntu7.20 ;;
    12)
      FIXED_VERSION=2.15-0ubuntu10.10 ;;
    14)
      FIXED_VERSION=2.19-0ubuntu6 ;;
  esac
else
  DEBIAN_RELEASE=$(lsb_release -sr | cut -c 1)
  case $DEBIAN_RELEASE in
    6)
      FIXED_VERSION=2.11.3-4+deb6u4 ;;
    7)
      FIXED_VERSION=2.13-38+deb7u7 ;;
    8)
      FIXED_VERSION=2.19-13 ;;
  esac
fi

dpkg --compare-versions $INSTALLED_VERSION gt $FIXED_VERSION
if [ ! $? -eq 0 ] ; then
  echo Installed is $INSTALLED_VERSION, should be $FIXED_VERSION
  exit 2
else
  echo Installed is $INSTALLED_VERSION, looks OK.
  exit 0
fi 

RHEL_GHOST_CHECK.sh

#!/bin/bash
RH_VER=$(cat /etc/redhat-release | cut -d " " -f 3 | cut -d "." -f 1 )
if [ "$RH_VER" ==  "5" ]; then
  GOOD_VER="glibc-2.5-123.el5_11.1"
fi
if [ "$RH_VER" ==  "6" ] || [ "$RH_VER" == "7" ]; then
  GOOD_VER="glibc-2.12-1.149.el6_6.5"
fi
CURRENT_VERSION=$(rpm -qa | grep glibc-2 | cut -d "." -f -5)
if [ "$CURRENT_VERSION" != "$GOOD_VER" ]; then
   echo "CURRENT VERSION IS $CURRENT_VERSION - SHOULD BE $GOOD_VER"
   exit 2
else
   echo "CURRENT VERSION ( $CURRENT_VERSION ) IS OK"
   exit 0
fi

Thanks - I couldn't work out how to merge it back, so I've just copied your version here :)