Buffer overflow in the FileReadGIF function in tkImgGIF.c for Tk Toolkit 8.4.12 and earlier, and 8.3.5 and earlier, allows user-assisted attackers to cause a denial of service (segmentation fault) via an animated GIF in which the first subimage is smaller than a subsequent subimage, which triggers the overflow in the ReadImage function, a different vulnerability than CVE-2007-5137.

Buffer overflow in the ReadImage function in generic/tkImgGIF.c in Tcl (Tcl/Tk) 8.4.13 through 8.4.15 allows remote attackers to execute arbitrary code via multi-frame interlaced GIF files in which later frames are smaller than the first. NOTE: this issue is due to an incorrect patch for CVE-2007-5378.