Please Install the Updated Packages.

Local exploitation of a memory corruption vulnerability in the X.Org and XFree86 X server could allow an attacker to execute arbitrary code with privileges of the X server, typically root. The vulnerability exists in the ProcXCMiscGetXIDList() function in the XC-MISC extension. This request is used to determine what resource IDs are available for use. This function contains two vulnerabilities, both result in memory corruption of either the stack or heap. The ALLOCATE_LOCAL() macro used by this function allocates memory on the stack using alloca() on systems where alloca() is present, or using the heap otherwise. The handler function takes a user provided value, multiplies it, and then passes it to the above macro. This results in both an integer overflow vulnerability, and an alloca() stack pointer shifting vulnerability. Both can be exploited to execute arbitrary code. (CVE-2007-1003) iDefense reported two integer overflows in the way X.org handled various font files. A malicious local user could exploit these issues to potentially execute arbitrary code with the privileges of the X.org server. (CVE-2007-1351, CVE-2007-1352) TightVNC uses some of the same code base as Xorg, and has the same vulnerable code. Updated packages are patched to address these issues.

tightvnc on Mandriva Linux 2007.0, Mandriva Linux 2007.0/X86_64