UofT CTF 2024

Out Of The Bucket [100 pts]

Check out my flag website!

Author: windex
https://storage.googleapis.com/out-of-the-bucket/src/index.html

We’re given a website

Checking out the website reveals two images and seemingly no suspicious files. I tried stegsolve with the images, but found nothing.

Eventually, I tried modifying the URL to see if there were any hidden files. Soon, I found something at https://storage.googleapis.com/out-of-the-bucket.

Here, a document tree was listed for the site in XML. Here it is:

This XML file does not appear to have any style information associated with it. The document tree is shown below.
<ListBucketResult>
<Name>out-of-the-bucket</Name>
<Prefix/>
<Marker/>
<IsTruncated>false</IsTruncated>
<Contents>
<Key>secret/</Key>
<Generation>1703868492595821</Generation>
<MetaGeneration>1</MetaGeneration>
<LastModified>2023-12-29T16:48:12.634Z</LastModified>
<ETag>"d41d8cd98f00b204e9800998ecf8427e"</ETag>
<Size>0</Size>
</Contents>
<Contents>
<Key>secret/dont_show</Key>
<Generation>1703868647771911</Generation>
<MetaGeneration>1</MetaGeneration>
<LastModified>2023-12-29T16:50:47.809Z</LastModified>
<ETag>"737eb19c7265186a2fab89b5c9757049"</ETag>
<Size>29</Size>
</Contents>
<Contents>
<Key>secret/funny.json</Key>
<Generation>1705174300570372</Generation>
<MetaGeneration>1</MetaGeneration>
<LastModified>2024-01-13T19:31:40.607Z</LastModified>
<ETag>"d1987ade72e435073728c0b6947a7aee"</ETag>
<Size>2369</Size>
</Contents>
<Contents>
<Key>src/</Key>
<Generation>1703867253127898</Generation>
<MetaGeneration>1</MetaGeneration>
<LastModified>2023-12-29T16:27:33.166Z</LastModified>
<ETag>"d41d8cd98f00b204e9800998ecf8427e"</ETag>
<Size>0</Size>
</Contents>
<Contents>
<Key>src/index.html</Key>
<Generation>1703867956175503</Generation>
<MetaGeneration>1</MetaGeneration>
<LastModified>2023-12-29T16:39:16.214Z</LastModified>
<ETag>"dc63d7225477ead6f340f3057263643f"</ETag>
<Size>1134</Size>
</Contents>
<Contents>
<Key>src/static/antwerp.jpg</Key>
<Generation>1703867372975107</Generation>
<MetaGeneration>1</MetaGeneration>
<LastModified>2023-12-29T16:29:33.022Z</LastModified>
<ETag>"cef4e40eacdf7616f046cc44cc55affc"</ETag>
<Size>45443</Size>
</Contents>
<Contents>
<Key>src/static/guam.jpg</Key>
<Generation>1703867372954729</Generation>
<MetaGeneration>1</MetaGeneration>
<LastModified>2023-12-29T16:29:32.993Z</LastModified>
<ETag>"f6350c93168c2955ceee030ca01b8edd"</ETag>
<Size>48805</Size>
</Contents>
<Contents>
<Key>src/static/style.css</Key>
<Generation>1703867372917610</Generation>
<MetaGeneration>1</MetaGeneration>
<LastModified>2023-12-29T16:29:32.972Z</LastModified>
<ETag>"0c12d00cc93c2b64eb4cccb3d36df8fd"</ETag>
<Size>76559</Size>
</Contents>
</ListBucketResult>

There are clearly some suspicious URLs. Visiting secret/dont_show gives us file containing the flag!

uoftctf{allUsers_is_not_safe}