libjbig2dec.a in Artifex jbig2dec 0.13, as used in MuPDF and Ghostscript, has a NULL pointer dereference in the jbig2_huffman_get function in jbig2_huffman.c. For example, the jbig2dec utility will crash (segmentation fault) when parsing an invalid file. https://nvd.nist.gov/vuln/detail/CVE-2017-9216
