AttackVector.tech

What is Directory Traversal?

Discover what Directory Traversal is and how attackers exploit it to access files beyond intended directories.

Explain Like I'm 5

Think of your computer system like a large hotel, with each room representing a different folder. You have a key to your room, but not to others. Directory Traversal is like sneaking into other rooms by exploiting a flaw in the hotel's security, using shared hallways instead of your key.

Hackers use Directory Traversal to access files they shouldn't, similar to someone finding a master key at the reception and using it to peek into all the rooms. They might read secret files, like the hotel's management plans or even private letters.

This is important because if someone can access sensitive files, they can steal secrets, cause damage, or mess with how the system works. It's like a thief knowing when rooms are empty so they can steal without getting caught.

Technical Definition

Definition

Directory Traversal, also known as Path Traversal, is a web security vulnerability that allows attackers to access directories and files stored outside the web root folder. This is achieved by manipulating variables referencing files with "../" sequences or through URL encoding.

How It Works

  1. 1Attackers input "../" sequences in URLs or input fields to traverse directories.
  2. 2They may use URL encoding techniques like "..%2f" or "..%2e%2e/" to bypass filters.
  3. 3Older systems might be vulnerable to null byte injections, where a %00 character terminates a string early, bypassing security checks.
  4. 4Successful traversal can expose sensitive files like '/etc/passwd', application configuration files, or source code.

Key Characteristics

  • Exploits lack of input validation or improper file path sanitization.
  • Often targets web servers but can affect any file-handling application.
  • Can be used in conjunction with other attacks, like Local File Inclusion (LFI).

Comparison

ConceptDescription
Directory TraversalAccesses files outside intended directories
Local File Inclusion (LFI)Executes or displays files on the server
Remote File Inclusion (RFI)Executes scripts from remote servers

Real-World Example

CVE-2021-41773 in Apache HTTP Server allowed attackers to perform a path traversal attack to map URLs to files outside the document root.

Detection & Prevention

  • Use tools like Burp Suite or ffuf to scan for traversal vulnerabilities.
  • Implement input validation and sanitize file paths.
  • Configure servers to deny access to sensitive files and directories.
  • Regularly update server software to patch known vulnerabilities.

Common Misconceptions

  • Myth: Directory Traversal only affects web servers. Truth: It can affect any application that improperly handles file paths.
  • Myth: Encoding will always prevent detection. Truth: Modern scanners and filters often detect encoded traversal attempts.
  • Myth: It's a minor issue. Truth: It can lead to severe breaches, exposing critical data and system functionality.

Keywords

what is Directory TraversalDirectory Traversal explainedDirectory Traversal detectionPath TraversalDirectory Traversal attackprevent Directory Traversal

Ready to scan your site?

AttackVector uses AI agents to find vulnerabilities before attackers do. Start a free scan now.

Start Free Scan