<p>Recently, Ma et al. proposed an efficient semi-quantum secret sharing protocol (SQSSP) for sharing specific secret information. In their protocol, quantum resources are provided by a trusted third party. The other participants, who act as classical parties, merely need to carry out classical operations to realize the sharing of specific secret information. Unfortunately, according to our security analysis, their protocol is insecure. When an external attacker conducts a Controlled-NOT (CNOT) attack, he/she can obtain the shared secret information without anyone's assistance. What is more, the attacker’s eavesdropping cannot be detected by the participants. During the execution of the protocol, the third party and the outside adversary can also obtain the shared secret information. Then, an improved scheme is proposed. The improved protocol can make up for the security defects of the original protocol, and it is secure against various types of attacks, including eavesdropping attacks and CNOT attack. Furthermore, it has enhanced security so that even trusted third party cannot obtain useful information about the shared secret. This protocol requires only semi-quantum capabilities for both the secret dealer and participants, and demonstrates advantages in quantum resources, security, and qubit efficiency compared to similar protocols.</p>