Versions of the package spatie/browsershot before 5.0.5 are vulnerable to Improper Input Validation in the setHtml function, invoked by Browsershot::html(), which can be bypassed by omitting the slashes in the file URI (e.g., file:../../../../etc/passwd). This is due to missing validations of the user input that should be blocking file URI schemes (e.g., file:// and file:/) in the HTML content.
The product receives input or data, but it does not validate or incorrectly validates that the input has the properties that are required to process the data safely and correctly.