Shescape is a simple shell escape package for JavaScript. Affected versions were found to have insufficient escaping of white space when interpolating output. This issue only impacts users that use the escape or escapeAll functions with the interpolation option set to true. The result is that if an attacker is able to include whitespace in their input they can: 1. Invoke shell-specific behaviour through shell-specific special characters inserted directly after whitespace. 2. Invoke shell-specific behaviour through shell-specific special characters inserted or appearing after line terminating characters. 3. Invoke arbitrary commands by inserting a line feed character. 4. Invoke arbitrary commands by inserting a carriage return character. Behaviour number 1 has been patched in [v1.5.7] which you can upgrade to now. No further changes are required. Behaviour number 2, 3, and 4 have been patched in [v1.5.8] which you can upgrade to now. No further changes are required. The best workaround is to avoid having to use the interpolation: true option - in most cases using an alternative is possible, see the recipes for recommendations. Alternatively, users may strip all whitespace from user input. Note that this is error prone, for example: for PowerShell this requires stripping '\u0085' which is not included in JavaScript's definition of \s for Regular Expressions.

Shescape is a shell escape package for JavaScript. An issue in versions 1.4.0 to 1.5.1 allows for exposure of the home directory on Unix systems when using Bash with the escape or escapeAll functions from the shescape API with the interpolation option set to true. Other tested shells, Dash and Zsh, are not affected. Depending on how the output of shescape is used, directory traversal may be possible in the application using shescape. The issue was patched in version 1.5.1. As a workaround, manually escape all instances of the tilde character (~) using arg.replace(/~/g, "\\~").