Lab: File path traversal, validation of file extension with null byte bypass

PRACTITIONER

This lab contains a file path traversal vulnerability in the display of product images.

The application validates that the supplied filename ends with the expected file extension.

To solve the lab, retrieve the contents of the /etc/passwd file.

Solution

Use Burp Suite to intercept and modify a request that fetches a product image.
Modify the filename parameter, giving it the value:
../../../etc/passwd%00.png
Observe that the response contains the contents of the /etc/passwd file.

Community solutions

zenshell

Intigriti

Michael Sommer

Maciej Pentester

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