Program: 101803
Project: 101803
Buggy source:
@EventHandler(priority=EventPriority.LOW,ignoreCancelled=true) public void checkExploit(PlayerMoveEvent event){
  Player player=event.getPlayer();
  Location from=event.getFrom();
  Location to=event.getTo();
  Distance distance=new Distance(from,to);
  double y=distance.getYDifference();
  backend.logAscension(player,from.getY(),to.getY());
  if (checkManager.willCheck(player,CheckType.SPEED) && backend.checkFreeze(player,from.getY(),to.getY())) {
    log("String_Node_Str",player,CheckType.SPEED);
    player.kickPlayer("String_Node_Str");
  }
  if (checkManager.willCheck(player,CheckType.SPRINT)) {
    if (backend.checkSprintStill(player,from,to)) {
      event.setCancelled(!config.silentMode());
      log("String_Node_Str",player,CheckType.SPRINT);
    }
  }
  if (checkManager.willCheck(player,CheckType.FLY) && !player.isFlying() && checkManager.willCheck(player,CheckType.ZOMBE_FLY)&& backend.checkFlight(player,distance)) {
    if (!config.silentMode()) {
      event.setTo(Anticheat.getManager().getUserManager().getUser(player.getName()).getGoodLocation(from.clone()));
    }
    log("String_Node_Str",player,CheckType.FLY);
  }
  if (checkManager.willCheck(player,CheckType.FLY) && !player.isFlying() && checkManager.willCheck(player,CheckType.ZOMBE_FLY)&& (backend.checkYAxis(player,distance) || backend.checkAscension(player,from.getY(),to.getY()))) {
    if (!config.silentMode()) {
      event.setTo(Anticheat.getManager().getUserManager().getUser(player.getName()).getGoodLocation(from.clone()));
    }
    log("String_Node_Str",player,CheckType.FLY);
  }
  if (checkManager.willCheck(player,CheckType.VCLIP) && checkManager.willCheck(player,CheckType.ZOMBE_FLY) && checkManager.willCheck(player,CheckType.FLY)&& event.getFrom().getY() > event.getTo().getY()) {
    int result=backend.checkVClip(player,new Distance(event.getFrom(),event.getTo()));
    if (result > 0) {
      if (!config.silentMode()) {
        Location newloc=new Location(player.getWorld(),event.getFrom().getX(),event.getFrom().getY() + result,event.getFrom().getZ());
        if (result > 3) {
          result=3;
        }
        if (newloc.getBlock().getTypeId() == 0) {
          event.setTo(newloc);
        }
 else {
          event.setTo(Anticheat.getManager().getUserManager().getUser(player.getName()).getGoodLocation(from.clone()));
        }
        player.damage(3);
      }
      log("String_Node_Str",player,CheckType.VCLIP);
    }
  }
  if (checkManager.willCheck(player,CheckType.NOFALL) && checkManager.willCheck(player,CheckType.ZOMBE_FLY) && checkManager.willCheck(player,CheckType.FLY)&& !Utilities.isClimbableBlock(player.getLocation().getBlock())&& event.getFrom().getY() > event.getTo().getY() && backend.checkNoFall(player,y)) {
    if (!config.silentMode()) {
      event.setTo(Anticheat.getManager().getUserManager().getUser(player.getName()).getGoodLocation(from.clone()));
      player.damage(2);
    }
    log("String_Node_Str",player,CheckType.NOFALL);
  }
  Anticheat.getManager().addEvent(event.getEventName(),event.getHandlers().getRegisteredListeners());
}

Fixed version (ground truth):
@EventHandler(priority=EventPriority.LOWEST,ignoreCancelled=true) public void checkExploit(PlayerMoveEvent event){
  Player player=event.getPlayer();
  Location from=event.getFrom();
  Location to=event.getTo();
  Distance distance=new Distance(from,to);
  double y=distance.getYDifference();
  backend.logAscension(player,from.getY(),to.getY());
  if (checkManager.willCheck(player,CheckType.SPEED) && backend.checkFreeze(player,from.getY(),to.getY())) {
    log("String_Node_Str",player,CheckType.SPEED);
    player.kickPlayer("String_Node_Str");
  }
  if (checkManager.willCheck(player,CheckType.SPRINT)) {
    if (backend.checkSprintStill(player,from,to)) {
      event.setCancelled(!config.silentMode());
      log("String_Node_Str",player,CheckType.SPRINT);
    }
  }
  if (checkManager.willCheck(player,CheckType.FLY) && !player.isFlying() && checkManager.willCheck(player,CheckType.ZOMBE_FLY)&& backend.checkFlight(player,distance)) {
    if (!config.silentMode()) {
      event.setTo(Anticheat.getManager().getUserManager().getUser(player.getName()).getGoodLocation(from.clone()));
    }
    log("String_Node_Str",player,CheckType.FLY);
  }
  if (checkManager.willCheck(player,CheckType.FLY) && !player.isFlying() && checkManager.willCheck(player,CheckType.ZOMBE_FLY)&& (backend.checkYAxis(player,distance) || backend.checkAscension(player,from.getY(),to.getY()))) {
    if (!config.silentMode()) {
      event.setTo(Anticheat.getManager().getUserManager().getUser(player.getName()).getGoodLocation(from.clone()));
    }
    log("String_Node_Str",player,CheckType.FLY);
  }
  if (checkManager.willCheck(player,CheckType.VCLIP) && checkManager.willCheck(player,CheckType.ZOMBE_FLY) && checkManager.willCheck(player,CheckType.FLY)&& event.getFrom().getY() > event.getTo().getY()) {
    int result=backend.checkVClip(player,new Distance(event.getFrom(),event.getTo()));
    if (result > 0) {
      if (!config.silentMode()) {
        Location newloc=new Location(player.getWorld(),event.getFrom().getX(),event.getFrom().getY() + result,event.getFrom().getZ());
        if (result > 3) {
          result=3;
        }
        if (newloc.getBlock().getTypeId() == 0) {
          event.setTo(newloc);
        }
 else {
          event.setTo(Anticheat.getManager().getUserManager().getUser(player.getName()).getGoodLocation(from.clone()));
        }
        player.damage(3);
      }
      log("String_Node_Str",player,CheckType.VCLIP);
    }
  }
  if (checkManager.willCheck(player,CheckType.NOFALL) && checkManager.willCheck(player,CheckType.ZOMBE_FLY) && checkManager.willCheck(player,CheckType.FLY)&& !Utilities.isClimbableBlock(player.getLocation().getBlock())&& event.getFrom().getY() > event.getTo().getY() && backend.checkNoFall(player,y)) {
    if (!config.silentMode()) {
      event.setTo(Anticheat.getManager().getUserManager().getUser(player.getName()).getGoodLocation(from.clone()));
      player.damage(2);
    }
    log("String_Node_Str",player,CheckType.NOFALL);
  }
  Anticheat.getManager().addEvent(event.getEventName(),event.getHandlers().getRegisteredListeners());
}