  We calculate the amount of entanglement shared by two intervals in the ground
state of a (1+1)-dimensional conformal field theory (CFT), quantified by an
entanglement measure $\mathcal{E}$ based on the computable cross norm (CCNR)
criterion. Unlike negativity or mutual information, we show that $\mathcal{E}$
has a universal expression even for two disjoint intervals, which depends only
on the geometry, the central charge c, and the thermal partition function of
the CFT. We prove this universal expression in the replica approach, where the
Riemann surface for calculating $\mathcal{E}$ at each order n is always a torus
topologically. By analytic continuation, result of n=1/2 gives the value of
$\mathcal{E}$. Furthermore, the results of other values of n also yield
meaningful conclusions: The n=1 result gives a general formula for the
two-interval purity, which enables us to calculate the Renyi-2 N-partite
information for N<=4 intervals; while the $n=\infty$ result bounds the
correlation function of the two intervals. We verify our findings numerically
in the spin-1/2 XXZ chain, whose ground state is described by the Luttinger
liquid.
