Can exploiters take advantage of this script?

I asked this question yesterday but never received a solution so I am going to ask again. I am really new to scripting and I am making a speed run game that will start the player's timer on their GUI when they touch a Part. The timer is saved as a leaderstat and I am using remote events to add to the timer. The touch event is in the player GUI and the calculations for the player's time are in the server script. Again, I am pretty new to scripting so is this a valid way of scripting my game while also preventing exploiters from tampering with their speed run times? Any help would be greatly appreciated

Local Script inside player's GUI

local ReplicatedStorage = game:GetService("ReplicatedStorage")

local remoteEvent = ReplicatedStorage:WaitForChild("ShowTime")
local Clear = ReplicatedStorage:WaitForChild("ClearTimeran")
local Replace = ReplicatedStorage:WaitForChild("Replace")


local SpeedBrick = workspace.RunBlock
local EndBrick = workspace.EndBlock

local go = true
local db = false
SpeedBrick.Touched:Connect(function(hit)
    local startplayer = game:GetService("Players"):GetPlayerFromCharacter(hit.Parent)
    if startplayer ~= nil and startplayer ==  game:GetService("Players").LocalPlayer then
        if db == false then
            db = true
            Clear:FireServer()
            repeat
                wait(0.1)
                remoteEvent:FireServer()

                ---SHOWING ON GUI---
                local player = script.Parent.Parent.Parent.Parent.Parent

                local leaderstats = player:WaitForChild("leaderstats")
                local stat = leaderstats:WaitForChild("runningtime") 
                local besttime = leaderstats:WaitForChild("time1")

                script.Parent.Text = stat.Value

                stat.Changed:Connect(function()
                    script.Parent.Text = stat.Value
                end)
                if stat.Value < besttime.Value then
                    local ColorNew = Color3.new(0.333333, 1, 0) --GREEN
                    script.Parent.TextColor3 = ColorNew
                end
                if stat.Value > besttime.Value and besttime.Value ~= 0 then
                    local ColorNew = Color3.new(1, 0, 0) --RED
                    script.Parent.TextColor3 = ColorNew
                end
                -------------------

                EndBrick.Touched:Connect(function(hit)
                    local endplayer = game:GetService("Players"):GetPlayerFromCharacter(hit.Parent)
                    if endplayer ~= nil and endplayer ==  game:GetService("Players").LocalPlayer then
                        go = false
                    end
                end)
            until go == false
        end
        wait(0.5)
        db = true
    end
    --Clearing timeran and replacing leveltime
    if go == false then
        local player = script.Parent.Parent.Parent.Parent.Parent
        local leaderstats = player:WaitForChild("leaderstats")
        local stat = leaderstats:WaitForChild("runningtime")
        local leveltime = leaderstats:WaitForChild("time1")
        if stat.Value < leveltime.Value then
            Replace:FireServer(leveltime,stat)
            script.Parent.Parent.BestTimeValue.Text = stat.Value
        elseif leveltime.Value == 0 then
            Replace:FireServer(leveltime,stat)
            script.Parent.Parent.BestTimeValue.Text = stat.Value
        end
    end
end)

Server Script

local remote = game:GetService("ReplicatedStorage")
local remoteEvent = remote:WaitForChild("ShowTime")

remoteEvent.OnServerEvent:Connect(function(player)  
    player.leaderstats.runningtime.Value = player.leaderstats.runningtime.Value + 0.1
end)

Please ask me if you need any more information. Thanks so much!