libjpeg null pointer dereference vulnerability (CNVD-2021-73917)

libjpeg is a free library written entirely in C to handle the JPEG image data format. libjpeg 2020021 and earlier versions of sampleinterleavedlsscan.cpp have a null pointer in the SampleInterleavedLSScan::ParseMCU() function to solve the reference vulnerability. An attacker could exploit this vulnerability to cause a denial of service.