Vulnerabilities > CVE-2018-18931 - Improper Privilege Management vulnerability in Trms Carousel Digital Signage 7.0.4.104
Summary
An issue was discovered in the Tightrope Media Carousel digital signage product 7.0.4.104. Due to insecure default permissions on the C:\TRMS\Services directory, an attacker who has gained access to the system can elevate their privileges from a restricted account to full SYSTEM by replacing the Carousel.Service.exe file with a custom malicious executable. This service is independent of the associated IIS web site, which means that this service can be manipulated by an attacker without losing access to vulnerabilities in the web interface (which would potentially be used in conjunction with this attack, to control the service). Once the attacker has replaced Carousel.Service.exe, the server can be restarted using the command "shutdown -r -t 0" from a web shell, causing the system to reboot and launching the malicious Carousel.Service.exe as SYSTEM on startup. If this malicious Carousel.Service.exe is configured to launch a reverse shell back to the attacker, then upon reboot the attacker will have a fully privileged remote command-line environment to manipulate the system further.
Vulnerable Configurations
| Part | Description | Count |
|---|---|---|
| Application | 2 |
Common Weakness Enumeration (CWE)
Common Attack Pattern Enumeration and Classification (CAPEC)
- Restful Privilege Elevation Rest uses standard HTTP (Get, Put, Delete) style permissions methods, but these are not necessarily correlated generally with back end programs. Strict interpretation of HTTP get methods means that these HTTP Get services should not be used to delete information on the server, but there is no access control mechanism to back up this logic. This means that unless the services are properly ACL'd and the application's service implementation are following these guidelines then an HTTP request can easily execute a delete or update on the server side. The attacker identifies a HTTP Get URL such as http://victimsite/updateOrder, which calls out to a program to update orders on a database or other resource. The URL is not idempotent so the request can be submitted multiple times by the attacker, additionally, the attacker may be able to exploit the URL published as a Get method that actually performs updates (instead of merely retrieving data). This may result in malicious or inadvertent altering of data on the server.