Abstract In 2010, Leander proposed a new version of the block cipher PRESENT with smaller block size, namely SMALLPRESENT-[n]. This algorithm is designed to deepen understanding of how the running time of the algorithm and the vulnerability of attack during the round increase with the number of rounds and s-boxes not determined on the algorithm. The boomerang attack is a variation of the differential attack introduced by Wagner in 1999. This attack uses two differential characteristics that are mutually independent in short rounds with high probability. This paper intends to present a lucid explanation of the boomerang attack. We illustrate the practical application of the boomerang attacks on two rounds of the SMALLPRESENT-[4], that includes the steps to find differential characteristic until key recovery, and explain the concept of attack for novice cryptanalysis. Based on experiments conducted, we found a boomerang differential characteristic on two rounds of SMALLPRESENT-[4] with a probability 2-10 and 4-bit subkey in the first round of the algorithm.