OpenClaw Shell Expansion Bypass Vulnerability in Unquoted Heredocs Allowing Exec Allowlist Bypass

A vulnerability in OpenClaw versions prior to 2026.4.22 allows for shell expansion bypass in unquoted heredoc bodies, creating an exec allowlist analysis vulnerability. Attackers can exploit this by embedding shell expansion tokens within heredocs to execute unauthorized commands at runtime, effectively circumventing allowlist validation.

Impact

Exploitation of this vulnerability could lead to unauthorized command execution by allowing hidden shell expansions in unquoted heredoc bodies to bypass exec allowlist validations.

Reproduction

The vulnerability can be reproduced by including shell expansion tokens, such as those representing environment variables or command substitutions, within an unquoted heredoc in a command that is subject to exec allowlist analysis. The command will be approved by the allowlist process but will execute the injected expansions at runtime, potentially leading to unauthorized actions or information disclosure.

Remediation

Users can upgrade to OpenClaw version 2026.4.22 or later, where this vulnerability has been fixed.