pi.c in OpenJPEG, as used in PDFium in Google Chrome before 48.0.2564.109, does not validate a certain precision value, which allows remote attackers to execute arbitrary code or cause a denial of service (out-of-bounds read) via a crafted JPEG 2000 image in a PDF document, related to the opj_pi_next_rpcl, opj_pi_next_pcrl, and opj_pi_next_cprl functions.
The product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary. This may result in read or write operations on unexpected memory locations that could be linked to other variables, data structures, or internal program data.