A maliciously crafted DLL file, when placed in the same directory as an RVT file could be loaded by Autodesk Revit, and execute arbitrary code in the context of the current process due to an untrusted search patch being utilized.
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.
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: