Despite the substantial amount of literature accumulated since the 1950s, the one referred to as D’yakov–Kontorovich (DK) instability, addressing the stability of steady shocks, is still unresolved when taking into account practical boundary conditions. The existing literature on steady shocks relies on a Fourier analysis to derive the dispersion relationship, but this only applies to isolated shock conditions. In reality, for a shock to be stable, it needs a supporting mechanism that can influence its dynamics through acoustic coupling. Classic works on steady shocks did not take into account this supporting mechanism, and thus, the dynamics of steady shocks in the presence of such driving mechanisms remains poorly understood. This study employs a theoretical unified approach to examine the stability of three distinct geometries of shock: the piston-driven planar shock; as well as the cylindrical and spherical steady expanding shocks. The latter two are associated with the Noh problem configurations. Through this research, we aim to provide a deeper understanding of the stability properties of these shocks, which could have important implications for various applications in physics and engineering.