Summary

It is a simple PoC of Improper Input Validation in python-gnupg 0.4.3 (CVE-2019-6690).

Vulnerable

• python python-gnupg 0.4.3
• python python-gnupg 0.3.6
• python python-gnupg 0.3.5
• python python-gnupg 0.3.4

Mitigation

Users should upgrade to 0.4.4

Test Environment

Docker Image

• docker pull avfisherdocker/python-gnupg0.4.3:CVE-2019-6690
• docker run -d -p 5000:5000 avfisherdocker/python-gnupg0.4.3:CVE-2019-6690

Proof of Concepts

1. apt install libmojolicious-perl
2. git clone https://github.com/brianwrf/CVE-2019-6690
3. cd CVE-2019-6690
4. perl exploit.pl <ip> <port>

Reference

• https://github.com/stigtsp/CVE-2019-6690-python-gnupg-vulnerability
• https://seclists.org/bugtraq/2019/Jan/41
• https://www.securityfocus.com/bid/106756