Proposed JEP: Safer Process Launch by ProcessBuilder and Runtime.exec

[Roger Riggs]

Hi Raffaello,

For .exe executables, one example is an empty string in the list of 
arguments to ProcessBuilder.
The empty string is not visible in the generated command line. For 
position sensitive commands, it appears the argument is dropped.
An argument in ProcessBuilder with mismatched quotes can cause the 
argument to be joined with the next in the generated command line.
A stray "\" at the end of an argument can cause the following character 
to be quoted, possibly joining the argument with the next.

For .cmd executables, cmd.exe interprets more characters as argument 
separators and will split arguments.
For example, an argument with a semi-colon or comma, (unquoted) will be 
split into two arguments when parsed by cmd.exe.
The goal is to improve the integrity and robustness of the command encoding.

Thanks, Roger


On 1/28/22 4:07 AM, Raffaello Giulietti wrote:
> Hello,
>
> if I understand correctly, the issue addressed here (on Windows) is 
> how to assemble a single command string from an array of argument 
> strings to pass to CreateProcess() in a way that the individual 
> argument strings can be fully recovered in the invoked program.
> Similarly when the command string is passed to an instance of cmd.exe.
>
> Are there known (non security critical) examples that do not work 
> correctly JDK 18 or earlier?
>
>
> Greetings
> Raffaello
>
>
> On 2022-01-20 19:05, Roger Riggs wrote:
>> A JEP to Improve safety of process launch by ProcessBuilder and 
>> Runtime.exec on Windows[1].
>>
>> Argument encoding errors have been problematic on Windows systems due to
>> improperly quoted command arguments.
>>
>> The idea is to tighten up quoting and encoding of command line 
>> arguments.
>>
>> Comments appreciated,  Roger
>>
>> [1] https://bugs.openjdk.java.net/browse/JDK-8263697