Buffer overflow in (1) X.Org Xserver before 1.4.1, and (2) the libfont and libXfont libraries on some platforms including Sun Solaris, allows context-dependent attackers to execute arbitrary code via a PCF font with a large difference between the last col and first col values in the PCF_BDF_ENCODINGS table.
The product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary. This may result in read or write operations on unexpected memory locations that could be linked to other variables, data structures, or internal program data.