CVE-2018-18930

/// Technical description

The Tightrope Media Carousel digital signage product 7.0.4.104 contains an arbitrary file upload vulnerability in the Manage Bulletins/Upload feature, which can be leveraged to gain remote code execution. An authenticated attacker can upload a crafted ZIP file (based on an exported backup of existing "Bulletins") containing a malicious file. When uploaded, the system only checks for the presence of the needed files within the ZIP and, as long as the malicious file is named properly, will extract all contained files to a new directory on the system, named with a random GUID. The attacker can determine this GUID by previewing an image from the uploaded Bulletin within the web UI. Once the GUID is determined, the attacker can navigate to the malicious file and execute it. In testing, an ASPX web shell was uploaded, allowing for remote-code execution in the context of a restricted IIS user.

/// Remediation

Check the references section for vendor advisories, patches, and mitigation guidance. If immediate patching is not possible, review the CVSS vector to understand the attack surface and apply compensating controls such as network segmentation or access restrictions.

/// References