A penetration tester is validating whether input validation mechanisms have been implemented in a web application.
Which of the following should the tester use to determine whether the application is vulnerable to path traversal attacks?
A penetration tester is validating whether input validation mechanisms have been implemented in a web application.
Which of the following should the tester use to determine whether the application is vulnerable to path traversal attacks?
To check for path traversal vulnerabilities, the tester needs to manipulate the file path in a manner that attempts to navigate outside the intended directory structure. This is typically done using sequences of '../' (URL-encoded as %2f..%2f) to move up the directory tree. Option A illustrates this method by attempting to access the /etc/hosts file via a series of encoded dot-dot-slash sequences. Therefore, this is the correct approach to test for path traversal attacks.
To determine whether the application is vulnerable to path traversal attacks, the penetration tester should use the following GET request: A. GET /image?filename-…%2f…%2f…%2f…%2f…%2f…%2fetc%2fhosts Path traversal attacks aim to access files and directories that are stored outside the web root folder by manipulating variables that reference files with “dot-dot-slash (…/)” sequences and its variations or by using absolute file paths. In option A, the filename parameter is manipulated to include multiple “…/” sequences to traverse up the directory tree and access the /etc/hosts file. Option B (GET /image?filename=lefitfe;pwd) is not related to path traversal attacks. Option C (POST /image?filename -) and option D (POST /image?filename =yhtak;ncat --ssl 192.168.0.1 2222) do not involve GET requests and are not related to path traversal attacks.
A. GET /image?filename=..%2f..%2f..%2f..%2f..%2f..%2fetc%2fhosts: This request includes a typical path traversal attack payload. The sequence of “../” (URL-encoded as “%2f”) attempts to navigate up the directory structure to access the /etc/hosts file. This is the correct method for testing path traversal vulnerabilities. B. GET /image?filename=lefitfe;pwd: This input attempts to inject a command (pwd) using a semicolon, which is more indicative of a command injection attempt rather than path traversal. C. POST /image?filename -: This input does not include any specific path traversal sequences and is incomplete, making it ineffective for testing path traversal. D. POST /image?filename=yhtak;ncat –ssl 192.168.0.1 2222: This input attempts to inject a command (ncat --ssl ...), which is more indicative of a command injection attempt rather than path traversal.
%2f = / .../.../.../.../ is direcory traversal