Hack-Proof The Node.js runtime: The Mechanics and Defense of Path Traversal Attacks

Are you decoding URLs before or after normalizing paths? The wrong order can expose every file on your Node.js server.

#1about 3 minutes

Defining path traversal and its severe impact

Path traversal is a vulnerability where attackers exploit insufficient validation of user-supplied file names to access restricted files, leading to information exposure and vulnerability chaining.

#2about 3 minutes

Examining high-impact path traversal exploits in the wild

Major software like Zimbra and Apache HTTP Server have suffered from critical, unauthenticated path traversal vulnerabilities leading to widespread system compromise.

#3about 7 minutes

How URL encoding bypassed security in the `st` package

Attackers bypassed path normalization in the popular `st` NPM package using URL-encoded characters, a vulnerability fixed by first decoding the URI component and then normalizing the path.

#4about 5 minutes

Exfiltrating local files via a VS Code extension

The "Open in Default Browser" VS Code extension contained a path traversal flaw that allowed attackers to trick users into exfiltrating local files like SSH keys.

#5about 4 minutes

A critical path traversal flaw in the Node.js runtime

A specific version of the Node.js runtime had an improper path sanitization issue that made applications vulnerable to directory traversal by default.

#6about 3 minutes

Key takeaways and tools for preventing path traversal

Path traversal is an omnipresent risk that can be mitigated by understanding API function order and using automated security scanning tools directly in your IDE.