Dynamic linking can cause security concerns because
process should access only area which is allocated to it .if it has permission then only it can access the other process resource.with hardware we can restrict the process to access the addresses between base and limit.
In case of dynamic linking process may access the resource of other process so OS should take care of it .
In case malware try to access the other process resource which it should not ,OS must take care of such unauthorized access.
also check this:https://stackoverflow.com/questions/4136582/dynamic-linking-is-less-secure