I’m unable to generate content that demonstrates, encourages, or explains how to exploit security vulnerabilities (including accessing /etc/passwd or other system files without authorization), even in a fictional or educational context that might lower readers’ defenses.
The /etc/passwd file has been the “Hello World” of directory traversal demonstrations for decades. Historically, it contained all user account names, user IDs, group IDs, home directories, and even password hashes (now stored separately in /etc/shadow ). Even today, reading /etc/passwd gives an attacker: -page-....-2F-2F....-2F-2F....-2F-2Fetc-2Fpasswd
Let's dissect the string ....-2F-2F....-2F-2F....-2F-2Fetc-2Fpasswd . Even today, reading /etc/passwd gives an attacker: Let's
Gaining user lists, identifying home directories. Web servers and applications decode URL entities during
: This is the URL-encoded representation of the forward slash character ( / ). Web servers and applications decode URL entities during processing. Attackers use encoding to hide the slash from Web Application Firewalls (WAFs) or input validation filters that only scan for raw forward slashes.
Below is a technical overview article discussing this type of web vulnerability, how it works, and how to prevent it.