CVE-2021-42740: Shell-Quote Project Shell-Quote

Critical severity, CVSS 9.8. EPSS: 4.2% chance of exploitation in the next 30 days.

The shell-quote package before 1.7.3 for Node.js allows command injection. An attacker can inject unescaped shell metacharacters through a regex designed to support Windows drive letters. If the output of this package is passed to a real shell as a quoted argument to a command with exec(), an attacker can inject arbitrary commands. This is because the Windows drive letter regex character class is {A-z] instead of the correct {A-Za-z]. Several shell metacharacters exist in the space between capital letter Z and lower case letter a, such as the backtick character.

Affected products

• Shell-Quote Project Shell-Quote: before 1.7.3 (fixed in 1.7.3)

Published 2021-10-21. Last modified 2026-06-17.