PDFKit is a framework for rendering of PDF content in GNUstep applications. ImageKits is a collection of frameworks to support imaging in GNUstep applications.
Maurycy Prodeus discovered an integer overflow vulnerability possibly leading to a stack-based buffer overflow in the XPDF code which PDFKit is based on. ImageKits also contains a copy of PDFKit.
By enticing a user to view a specially crafted PDF file with a viewer based on ImageKits or PDFKit such as Gentoo's ViewPDF, a remote attacker could cause an overflow, potentially resulting in the execution of arbitrary code with the privileges of the user running the application.
There is no known workaround at this time.
PDFKit and ImageKits are not maintained upstream, so the packages were masked in Portage. We recommend that users unmerge PDFKit and ImageKits:
# emerge --unmerge gnustep-libs/pdfkit
# emerge --unmerge gnustep-libs/imagekits
As an alternative, users should upgrade their systems to use PopplerKit instead of PDFKit and Vindaloo instead of ViewPDF.