Zip Slip

The vulnerability is exploited using a specially crafted archive that holds directory traversal filenames (e.g. ../../shell.php). The Zip Slip vulnerability can affect numerous archive formats, including tar, jar, war, cpio, apk, rar and 7z. The attacker can then overwrite executable files and either invoke them remotely or wait for the system or user to call them, thus achieving remote command execution on the victim’s machine.

Summary

• Detection
• Tools
• Exploits
• Basic Exploit
• Additional Notes

Detection

• Any zip upload page on the application

Tools

• evilarc
• slipit

Exploits

Basic Exploit

Using evilarc:

python evilarc.py shell.php -o unix -f shell.zip -p var/www/html/ -d 15

Additional Notes

• For affected libraries and projects, visit https://github.com/snyk/zip-slip-vulnerability

References

• Zip Slip Vulnerability - Snyk Ltd, 2019
• Zip Slip - snyk, 2019