The PostScriptFunction::PostScriptFunction function in poppler/Function.cc in the PDF parser in poppler 0.8.7 and possibly other versions up to 0.15.1, and possibly other products, allows context-dependent attackers to cause a denial of service (crash) via a PDF file that triggers an uninitialized pointer dereference.
The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.