Summary

A command injection vulnerability (CWE-78) has been found to exist in the wrangler pages deploy command. The issue occurs because the --commit-hash parameter is passed directly to a shell command without proper validation or sanitization, allowing an attacker with control of --commit-hash to execute arbitrary commands on the system running Wrangler.

Root cause

The commitHash variable, derived from user input via the --commit-hash CLI argument, is interpolated directly into a shell command using template literals (e.g., execSync(git show -s --format=%B ${commitHash})). Shell metacharacters are interpreted by the shell, enabling command execution.

Impact

This vulnerability is generally hard to exploit, as it requires --commit-hash to be attacker controlled. The vulnerability primarily affects CI/CD environments where wrangler pages deploy is used in automated pipelines and the --commit-hash parameter is populated from external, potentially untrusted sources. An attacker could exploit this to:

- Run any shell command. - Exfiltrate environment variables. - Compromise the CI runner to install backdoors or modify build artifacts.

Mitigation

- Wrangler v4 users are requested to upgrade to Wrangler v4.59.1 or higher. - Wrangler v3 users are requested to upgrade to Wrangler v3.114.17 or higher. - Users on Wrangler v2 (EOL) should upgrade to a supported major version.

Credits

Disclosed responsibly by kny4hacker.