refractor blogpost and cdn chall

services/cdn/README.md

@@ -1,30 +0,0 @@
-## CDN
-
-db used: sqlite
-flag.txt: GEMASTIK{random sha256 generated on app start}
-
-### feature:
-[authentication required with login and register, register default as "user" role]
-1. upload image
-
-### Vulns
-#### vuln1: SSTI on image Date Created metadata, exiftool cant insert this, need to write the image's blob
-example: 
-```bash
-(base) jons@01-20-jonathanmarbun:/mnt/c/1Jonathan/CTFS/gawe/gms25/web2/exploit$ exiftool -overwrite_original -IPTC:DateCreated="{{7*7}}" image.png
-Warning: Invalid date format (use YYYY:mm:dd) in IPTC:DateCreated (ValueConvInv)
-Nothing to do.
-```
-payload to inject:
-```{{lipsum.__builtins__['open']('flag.txt').read()}}```
-
-when editing the Date Created metadata manually, somehow it has limit of 46 char (but we can expand that to make it more by deleting the content of another metadata) -> check ssti.png
-it probably have different behavior on another image file or format
-payload: check exploit/exp3.py
-
-#### vuln2: 
-
-### Patching Rule?
-- dont remove flag.txt/changes its content
-- ensure image metadata generation still available
-- ensure exiftool still used