Not Today

Description

Not Today | 75 points | By Mudasir Ali

This website gives you the flag sometimes. When it feels like it. In a special time zone. Time Zone: GMT+∀ (BCA Special Time) Date Time: Wed Jun 07 2023 06:09:42

Web servers: challs.bcactf.com:30603

Analysis

The index.html contains this script which makes call to api and returns flag.

<script>
    const today = new Date();
    fetch('/api', {
        method: 'POST',
        headers: {'Content-Type': 'application/json'},
        body: JSON.stringify({date: today.toString()})
    })
    .then(response => response.json())
    .then(data => { document.getElementById('flag').innerHTML = data.flag; });
</script>

Solution

As described by above it needs a specific time. Open console on the same page and run.

fetch('/api', {
    method: 'POST',
    headers: {'Content-Type': 'application/json'},
    body: JSON.stringify({date: "Wed Jun 07 2023 06:09:42 GMT+∀ (BCA Special Time)"})
})
.then(response => response.json())
.then(data => { console.log(data.flag);});

Flag: bcactf{y0U_m@d3_hT7p_H!$70rY?!_HDU38rndu8}