Severity: critical

Potential Command Injection

shell-quote

Overview

Affected versions of shell-quote do not properly escape command line arguments, which may result in command injection if the library is used to escape user input destined for use as command line arguments.

Proof of Concept:

The following characters are not escaped properly: >,;,{,}

Bash has a neat but not well known feature known as "Bash Brace Expansion", wherein a sub-command can be executed without spaces by running it between a set of {} and using the , instead of to seperate arguments. Because of this, full command injection is possible even though it was initially thought to be impossible.

   const quote = require('shell-quote').quote;
   console.log(quote(['a;{echo,test,123,234}']));
   // Actual                    "a;{echo,test,123,234}"
   // Expected                  "a\;\{echo,test,123,234\}"
   // Functional Equivalent     "a; echo 'test' '123' '1234'"

Remediation

Update to version 1.6.1 or later.

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Advisory timeline

  1. published

    Advisory published
    Jun 21st, 2016
  2. reported

    May 16th, 2016