The gcc and gcc4 packages include, among others, C, C++, and Java GNU compilers and related support libraries. libgcj contains a copy of GNU Libtool"s libltdl library. A flaw was found in the way GNU Libtool"s libltdl library looked for libraries to load. It was possible for libltdl to load a malicious library from the current working directory. In certain configurations, if a local attacker is able to trick a local user into running a Java application from within an attacker-controlled directory containing a malicious library or module, the attacker could possibly execute arbitrary code with the privileges of the user running the Java application. All gcc and gcc4 users should upgrade to these updated packages, which contain a backported patch to correct this issue. All running Java applications using libgcj must be restarted for this update to take effect.