Recently, Ivanov et al. proposed a new approach to construct code-based cryptosystems, namely the IKKR public-key encryptions (PKE) in the International Workshop on Code-Based Cryptography (CBCrypto 2020) [9]. Unlike the usual construction in code-based encryption schemes which has restrictions on the Hamming weight of the error introduced into the ciphertext, the IKKR approach allows error vectors of arbitrary weight being introduced into the ciphertext. Using this new approach, Ivanov et al. constructed two cryptosystems, namely the modified and the upgraded IKKR-PKE. This paper aims to discuss the practical security of the IKKR-PKE. In particular, we describe the weaknesses in the design of the public key used in the IKKR-PKE. We exploit such weaknesses and propose two attacks to recover the plaintext in the IKKR-PKE. The approach of our first attack is similar to the LCKN attack [12], whilst our second attack is more efficient than the LCKN attack. Our experimental results show that we can recover the plaintext from a given ciphertext in less than 176 milliseconds for schemes based on random Goppa codes and BCH codes.