The heartbleed bug was introduced in OpenSSL 1.0.1 and is present in

1.0.1
1.0.1a
1.0.1b
1.0.1c
1.0.1d
1.0.1e
1.0.1f

The bug is NOT PRESENT in 1.0.1g, 1.0.0 and 0.9.8 branch of OpenSSL.

Check Arch Linux 

pacman -Q openssl
local/openssl 1.0.1.f-1    

If you see any version above you need to patch Arclinux

pacman -Sy ; pacman -S openssl ;

Check rpm based systems Centos/RedHat/Oracle Linux

rpm -qa |grep openssl
openssl-1.0.0

If you see any version above you need to patch OS

yum update openssl