Cloud 2 - Time Travel

Challenge Information

• Name: Cloud 2 - Time Travel
• Points: 100
• Category: Cloud
• Objective: Retrieve an older version of a file (flag.txt) stored in an AWS S3 bucket.

Solution

GUI Approach

1. Append /?versions to the challenge-provided URL to access the versioning view of the S3 bucket.

   • Example: http://<bucket-url>/?versions

2. Observe two versions of flag.txt:

   • One is 70 KB, and the other is 71 KB.

   

3. As far as I know, GUI does not support direct access to older versions of the file

4. Hence, CLI is required to proceed

5. But I might be wrong

CLI Approach

1. Check S3 Bucket Versioning: Use the following command to confirm bucket versioning and list available versions

   1	aws s3api get-bucket-versioning --bucket <s3-bucket-name>

2. List Object Versions: Retrieve all versions of flag.txt with

   1	aws s3api list-object-versions --bucket <s3-bucket-name> --prefix "flag.txt"

3. Retrieve the Old File: Use the specific VersionId for the older version (e.g., KjCs3l2ZKNtHVTKB1R8IdzoidxwuQwFt) to download the file

   1 2 3 4

   aws s3api get-object --bucket <bucket>\ --key "flag.txt" \ --version-id "KjCs3l2ZKNtHVTKB1R8IdzoidxwuQwFt" \ oldflag --profile ccx