Commit message: https://github.com/ImageMagick/ImageMagick/issues/1162
CVE: CVE-2018-16642
CWE: CWE-787
Vulnerability description: The function InsertRow in coders/cut.c in ImageMagick 7.0.7-37 allows remote attackers to cause a denial of service via a crafted image file due to an out-of-bounds write.

Project: ImageMagick

static void InsertRow(Image *image,ssize_t depth,unsigned char *p,ssize_t y,
static MagickBooleanType InsertRow(Image *image,ssize_t bpp,unsigned char *p,
  ssize_t y,ExceptionInfo *exception)
 {
  int
    bit;
 
  Quantum
    index;

  register Quantum
    *q;

  ssize_t
    x;

  q=QueueAuthenticPixels(image,0,y,image->columns,1,exception);
  if (q == (Quantum *) NULL)
    return(MagickFalse);
  switch (bpp)
    {
     case 1:  /* Convert bitmap scanline. */
       {
         for (x=0; x < ((ssize_t) image->columns-7); x+=8)
         {
           for (bit=0; bit < 8; bit++)
           {
            index=((*p) & (0x80 >> bit) ? 0x01 : 0x00);
             SetPixelIndex(image,index,q);
            if (index < image->colors)
              SetPixelViaPixelInfo(image,image->colormap+(ssize_t) index,q);
             q+=GetPixelChannels(image);
           }
           p++;
         }
         if ((image->columns % 8) != 0)
           {
            for (bit=0; bit < (ssize_t) (image->columns % 8); bit++)
            {
              index=((*p) & (0x80 >> bit) ? 0x01 : 0x00);
              SetPixelIndex(image,index,q);
              if (index < image->colors)
                SetPixelViaPixelInfo(image,image->colormap+(ssize_t) index,q);
              SetPixelViaPixelInfo(image,image->colormap+(ssize_t) index,q);
              q+=GetPixelChannels(image);
            }
             p++;
           }
         break;
       }
     case 2:  /* Convert PseudoColor scanline. */
       {
        for (x=0; x < ((ssize_t) image->columns-3); x+=4)
         {
            index=ConstrainColormapIndex(image,(*p >> 6) & 0x3,exception);
            SetPixelIndex(image,index,q);
            if (index < image->colors)
              SetPixelViaPixelInfo(image,image->colormap+(ssize_t) index,q);
            q+=GetPixelChannels(image);
            index=ConstrainColormapIndex(image,(*p >> 4) & 0x3,exception);
            SetPixelIndex(image,index,q);
            if (index < image->colors)
              SetPixelViaPixelInfo(image,image->colormap+(ssize_t) index,q);
            q+=GetPixelChannels(image);
            index=ConstrainColormapIndex(image,(*p >> 2) & 0x3,exception);
            SetPixelIndex(image,index,q);
            if (index < image->colors)
              SetPixelViaPixelInfo(image,image->colormap+(ssize_t) index,q);
            q+=GetPixelChannels(image);
            index=ConstrainColormapIndex(image,(*p) & 0x3,exception);
            SetPixelIndex(image,index,q);
            if (index < image->colors)
              SetPixelViaPixelInfo(image,image->colormap+(ssize_t) index,q);
            q+=GetPixelChannels(image);
            p++;
         }
       if ((image->columns % 4) != 0)
           {
             index=ConstrainColormapIndex(image,(*p >> 6) & 0x3,exception);
             SetPixelIndex(image,index,q);
            if (index < image->colors)
              SetPixelViaPixelInfo(image,image->colormap+(ssize_t) index,q);
             q+=GetPixelChannels(image);
            if ((image->columns % 4) > 1)
               {
                 index=ConstrainColormapIndex(image,(*p >> 4) & 0x3,exception);
                 SetPixelIndex(image,index,q);
                if (index < image->colors)
                  SetPixelViaPixelInfo(image,image->colormap+(ssize_t) index,q);
                 q+=GetPixelChannels(image);
                if ((image->columns % 4) > 2)
                   {
                     index=ConstrainColormapIndex(image,(*p >> 2) & 0x3,
                       exception);
                     SetPixelIndex(image,index,q);
                    if (index < image->colors)
                      SetPixelViaPixelInfo(image,image->colormap+(ssize_t)
                        index,q);
                     q+=GetPixelChannels(image);
                   }
               }
             p++;
           }
         break;
       }
 
     case 4:  /* Convert PseudoColor scanline. */
       {
         for (x=0; x < ((ssize_t) image->columns-1); x+=2)
          {
            index=ConstrainColormapIndex(image,(*p >> 4) & 0x0f,exception);
             SetPixelIndex(image,index,q);
            if (index < image->colors)
              SetPixelViaPixelInfo(image,image->colormap+(ssize_t) index,q);
             q+=GetPixelChannels(image);
            index=ConstrainColormapIndex(image,(*p) & 0x0f,exception);
             SetPixelIndex(image,index,q);
            if (index < image->colors)
              SetPixelViaPixelInfo(image,image->colormap+(ssize_t) index,q);
             p++;
            q+=GetPixelChannels(image);
           }
         if ((image->columns % 2) != 0)
           {
            index=ConstrainColormapIndex(image,(*p >> 4) & 0x0f,exception);
             SetPixelIndex(image,index,q);
            if (index < image->colors)
              SetPixelViaPixelInfo(image,image->colormap+(ssize_t) index,q);
             p++;
            q+=GetPixelChannels(image);
           }
         break;
       }
     case 8: /* Convert PseudoColor scanline. */
       {
         for (x=0; x < (ssize_t) image->columns; x++)
          {
            index=ConstrainColormapIndex(image,*p,exception);
            SetPixelIndex(image,index,q);
            if (index < image->colors)
              SetPixelViaPixelInfo(image,image->colormap+(ssize_t) index,q);
            p++;
            q+=GetPixelChannels(image);
          }
      }
      break;

    case 24:     /*  Convert DirectColor scanline.  */
      for (x=0; x < (ssize_t) image->columns; x++)
         {
          SetPixelRed(image,ScaleCharToQuantum(*p++),q);
          SetPixelGreen(image,ScaleCharToQuantum(*p++),q);
          SetPixelBlue(image,ScaleCharToQuantum(*p++),q);
           q+=GetPixelChannels(image);
         }
      break;
     }
  if (!SyncAuthenticPixels(image,exception))
    return(MagickFalse);
  return(MagickTrue);
 }