An issue was discovered in PureVPN through 5.19.4.0 on Windows. The client installation grants the Everyone group Full Control permission to the installation directory. In addition, the PureVPNService.exe service, which runs under NT AuthoritySYSTEM privileges, tries to load several dynamic-link libraries using relative paths instead of the absolute path. When not using a fully qualified path, the application will first try to load the library from the directory from which the application is started. As the residing directory of PureVPNService.exe is writable to all users, this makes the application susceptible to privilege escalation through DLL hijacking.
The product searches for critical resources using an externally-supplied search path that can point to resources that are not under the product’s direct control.
| Name | Vendor | Start Version | End Version |
|---|---|---|---|
| Purevpn | Purevpn | 5.19.4.0 (including) | 5.19.4.0 (including) |
This might allow attackers to execute their own programs, access unauthorized data files, or modify configuration in unexpected ways. If the product uses a search path to locate critical resources such as programs, then an attacker could modify that search path to point to a malicious program, which the targeted product would then execute. The problem extends to any type of critical resource that the product trusts. Some of the most common variants of untrusted search path are: