Array index error in the (1) torisa.c and (2) dahdi/tor2.c drivers in Zaptel (aka DAHDI) 1.4.11 and earlier allows local users in the dialout group to overwrite an integer value in kernel memory by writing to /dev/zap/ctl, related to missing validation of the sync field associated with the ZT_SPANCONFIG ioctl.
CWE-189