(RHSA-2008:0134) Moderate: tcltk security update

Tcl is a scripting language designed for embedding into other applications
and for use with Tk, a widget set.

An input validation flaw was discovered in Tk’s GIF image handling. A
code-size value read from a GIF image was not properly validated before
being used, leading to a buffer overflow. A specially crafted GIF file
could use this to cause a crash or, potentially, execute code with the
privileges 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 images
could cause a crash or, potentially, execute code with the privileges of
the application using the Tk library. (CVE-2007-5378)

A flaw in the Tcl regular expression handling engine was discovered by Will
Drewry. This flaw, first discovered in the Tcl regular expression engine
used in the PostgreSQL database server, resulted in an infinite loop when
processing certain regular expressions. (CVE-2007-4772)

All users are advised to upgrade to these updated packages which contain
backported patches which resolve these issues.