Integer overflow in the CIDAFM function in X.Org 6.8.2 and XFree86 X server allows local users to execute arbitrary code via crafted Adobe Font Metrics (AFM) files with a modified number of character metrics (StartCharMetrics), which leads to a heap-based buffer overflow.

Integer overflow in the scan_cidfont function in X.Org 6.8.2 and XFree86 X server allows local users to execute arbitrary code via crafted (1) CMap and (2) CIDFont font data with modified item counts in the (a) begincodespacerange, (b) cidrange, and (c) notdefrange sections.

The XClientMessageEvent struct used in certain components of X.Org 6.8.2 and earlier, possibly including (1) the X server and (2) Xlib, uses a "long" specifier for elements of the l array, which results in inconsistent sizes in the struct on 32-bit versus 64-bit platforms, and might allow attackers to cause a denial of service (application crash) and possibly conduct other attacks.