Vulnerability details

### Summary `launch-editor` did not escape `%` on Windows when passing an argument to `cmd`. When an environment variable contained a malicious value, it was possible that that content to be executed. ### Impact Only apps that match all of the following conditions are affected: - The user uses Windows - An attacker can place a file with the malicious filename containing `&` or `%` - Either of - An attacker can inject an environment variable with a malicious value - An attacker can add a NTFS alternate data stream to the file placed ### Details Unlike `.sh` files, `.bat` / `.cmd` files on Windows cannot be called directly using [`child_process.spawn`](https://nodejs.org/docs/latest-v24.x/api/child_process.html#child_processspawncommand-args-options) and requires passing them as an argument of `cmd.exe`. To do so, launch-editor escapes the arguments passed to `cmd.exe`. But `launch-editor` did not escape `%` which is used for environment variables. Because `launch-editor` checks if the argument matches an existing filename, the attack requires the attacker to be able to place a file. - If the attacker can inject an environment variable as well, they can include the subcommand in the env variable (e.g. set ` &calc.exe ` to `%ENV%`) and call `launchEditor` with `something%ENV%`. - If the attacker can place a NTFS alternate data stream to the file (e.g. a NTFS alternate data stream named `~-38%calc.exe`), they can call `launchEditor` with `something %CMDCMDLINE:~-38%calc.exe`. - If the attacker can create a filename containing the `%CD%` and the subcommand (e.g. `&calc.exe `), they can call `launchEditor` with `./%CD%`