ExpressVPN on Windows Service Port 2015 Xvpnd.exe XVPN.GetPreference/XVPN.SetPreference path traversal

Summaryinfo

A vulnerability classified as critical was found in ExpressVPN on Windows. The affected element is the function XVPN.GetPreference/XVPN.SetPreference of the file Xvpnd.exe of the component Service Port 2015. Such manipulation leads to path traversal. This vulnerability is listed as CVE-2018-15490. The attack must be carried out locally. There is no available exploit. Restrictive firewalling should be applied.

Detailsinfo

A vulnerability was found in ExpressVPN on Windows (version unknown). It has been rated as critical. Affected by this issue is the function XVPN.GetPreference/XVPN.SetPreference of the file Xvpnd.exe of the component Service Port 2015. The manipulation with an unknown input leads to a path traversal vulnerability. Using CWE to declare the problem leads to CWE-22. The product uses external input to construct a pathname that is intended to identify a file or directory that is located underneath a restricted parent directory, but the product does not properly neutralize special elements within the pathname that can cause the pathname to resolve to a location that is outside of the restricted directory. Impacted is confidentiality, integrity, and availability. CVE summarizes:

An issue was discovered in ExpressVPN on Windows. The Xvpnd.exe process (which runs as a service with SYSTEM privileges) listens on TCP port 2015, which is used as an RPC interface for communication with the client side of the ExpressVPN application. A JSON-RPC protocol over HTTP is used for communication. The JSON-RPC XVPN.GetPreference and XVPN.SetPreference methods are vulnerable to path traversal, and allow reading and writing files on the file system on behalf of the service.

The bug was discovered 12/31/2018. The weakness was presented 01/02/2019 (Website). The advisory is available at medium.com. This vulnerability is handled as CVE-2018-15490 since 08/17/2018. The exploitation is known to be easy. Local access is required to approach this attack. No form of authentication is required for exploitation. Technical details are known, but there is no available exploit. This vulnerability is assigned to T1006 by the MITRE ATT&CK project.

The vulnerability was handled as a non-public zero-day exploit for at least 2 days. During that time the estimated underground price was around $0-$5k. The commercial vulnerability scanner Qualys is able to test this issue with plugin 371642 (ExpressVPN local privilege escalation Vulnerability).

Addressing this vulnerability is possible by firewalling tcp/2015.

If you want to get best quality of vulnerability data, you may have to visit VulDB.

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• ExpressVPN

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• 🔍

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• 🔍

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If you want to get best quality of vulnerability data, you may have to visit VulDB.

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