Tk is a graphical toolkit for the Tcl scripting language.An input validation flaw was discovered in Tk's GIF image handling. Acode-size value read from a GIF image was not properly validated beforebeing used, leading to a buffer overflow. A specially crafted GIF filecould use this to cause a crash or, potentially, execute code with theprivileges of the application using the Tk graphical toolkit.(CVE-2008-0553)A buffer overflow flaw was discovered in Tk's animated GIF image handling.An animated GIF containing an initial image smaller than subsequent imagescould cause a crash or, potentially, execute code with the privileges ofthe application using the Tk library. (CVE-2007-5137)All users are advised to upgrade to these updated packages which contain abackported patches to resolve these issues.