This work investigates the effect of a porous medium/permeable wall in the region of flow separation induced by an impinging oblique shock/boundary-layer interaction (SBLI) at Mach 2.0 using 2D numerical simulations. The study presented here includes an investigation of cases with no control, with permeable walls, and wavy non-permeable walls with varying waviness. The effect of the position and extent of the permeable wall is also investigated. The porous region is modeled as a cavity filled with a square array of circular cylinders (rendered as circles in 2D). The computations are performed using a parallel, finite-volume solver for compressible flows on structured grids. An immersed-boundary method is used to represent the porous region. Menter’s k − ω SST model is used to model turbulence. Results are presented using pressure contours (to reveal shock structure), streamline patterns, and near-surface velocity and pressure. It is observed from the plots that the limiting case of a non-permeable wall produces better results compared to the permeable wall, indicating that passive blowing (from) and suction (into) the permeable wall does not produce the desired effect of energizing the boundary layer and mitigating flow separation in this case. © 2021, American Institute of Aeronautics and Astronautics Inc, AIAA. All rights reserved.