As Jason already mentioned, everything depends on file. But I want to say something more.
And, imagine that you can gain control over the Parameters argument.
Does that mean it is exploitable ?
In the same manner control of other
ShellExecute parameters might be gain... You probably understand why I said might, not can.
You didn't included info in question, but I think you meant that control of
parameters is gained editing executable. If so there is such thing.
Imagine file is
cmd.exe and you can control parameters, but in app parameter is
C:\file.txt it has 11 characters, so you could change it into some other up-to 11 characters parameter (if it is smaller then 11, you need to add
However in real situations
ShellExecute parameters are partially hard-coded and are build dynamically during program flow. So answering to your question,
ShellExecute is vulnerable to command injection, however, not every app that uses
ShellExecute could be taken as a target and actual injecting could be not so easy task.