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@apostrophecms/cli: Command Injection in apos create via Unsanitized Password Input

Moderate severity GitHub Reviewed Published May 13, 2026 in apostrophecms/apostrophe • Updated May 14, 2026

Package

npm @apostrophecms/cli (npm)

Affected versions

<= 3.6.0

Patched versions

None

Description

Summary

The @apostrophecms/cli package contains a command injection vulnerability in the apos create command.
User-supplied input from the password prompt is embedded directly into a shell command without proper sanitization or escaping.
This allows execution of arbitrary commands on the host system.

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Details

Vulnerable file: lib/commands/create.js
Location: Line 186

The CLI collects a password using an interactive prompt and passes it directly into a shell command.

Vulnerable code:

const response = await prompts({
type: 'password',
name: 'pw',
message: '🔏 Please enter a password:'
});

exec(echo "${response.pw}" | ${createUserCommand});

The value of response.pw is not validated, sanitized, or escaped before being used in exec().

This allows shell metacharacters such as ;, &&, and $() to break out of the intended command and execute arbitrary commands.

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Steps to Reproduce

  1. Install the CLI
    npm install -g @apostrophecms/cli
  2. Create a new project
    mkdir testproject && cd testproject
    apos create mysite
    3)When prompted for the admin password, enter
    "; id > /tmp/apos_rce_proof.txt; echo "
    4)Verify command execution
    cat /tmp/apos_rce_proof.txt

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Proof of Concept Output

uid=1000(vboxuser) gid=1000(vboxuser) groups=1000(vboxuser),27(sudo),984(docker)

This confirms arbitrary command execution with the privileges of the user running the CLI.

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Impact

Arbitrary command execution on the developer’s machine
Execution occurs with the privileges of the user running the CLI

This can lead to:

File modification or deletion
Credential exposure
System compromise depending on user privileges

An attacker can exploit this by influencing the password input (for example, through social engineering, malicious documentation, or compromised automation scripts).

The proof-of-concept shows execution under a user belonging to privileged groups such as sudo and docker, which may allow further privilege escalation depending on system configuration.

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Suggested Fix

Avoid using exec() with user-controlled input.

Use execFile() instead:

const { execFileSync } = require('child_process');

execFileSync('node', [appJsPath, userTask, 'admin', 'admin'], {
input: response.pw + '\n'
});

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Affected Version

All current versions of @apostrophecms/cli

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Tested On

Ubuntu 22.04
Node.js v18.19.1

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CWE

CWE-78 — Improper Neutralization of Special Elements used in an OS Command

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References

@boutell boutell published to apostrophecms/apostrophe May 13, 2026
Published to the GitHub Advisory Database May 14, 2026
Reviewed May 14, 2026
Last updated May 14, 2026

Severity

Moderate

CVSS overall score

This score calculates overall vulnerability severity from 0 to 10 and is based on the Common Vulnerability Scoring System (CVSS).
/ 10

CVSS v3 base metrics

Attack vector
Local
Attack complexity
Low
Privileges required
High
User interaction
Required
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS v3 base metrics

Attack vector: More severe the more the remote (logically and physically) an attacker can be in order to exploit the vulnerability.
Attack complexity: More severe for the least complex attacks.
Privileges required: More severe if no privileges are required.
User interaction: More severe when no user interaction is required.
Scope: More severe when a scope change occurs, e.g. one vulnerable component impacts resources in components beyond its security scope.
Confidentiality: More severe when loss of data confidentiality is highest, measuring the level of data access available to an unauthorized user.
Integrity: More severe when loss of data integrity is the highest, measuring the consequence of data modification possible by an unauthorized user.
Availability: More severe when the loss of impacted component availability is highest.
CVSS:3.1/AV:L/AC:L/PR:H/UI:R/S:U/C:H/I:H/A:H

EPSS score

Weaknesses

Improper Neutralization of Special Elements used in an OS Command ('OS Command Injection')

The product constructs all or part of an OS command using externally-influenced input from an upstream component, but it does not neutralize or incorrectly neutralizes special elements that could modify the intended OS command when it is sent to a downstream component. Learn more on MITRE.

CVE ID

CVE-2026-42853

GHSA ID

GHSA-hcwq-x9fw-8cfq

Credits

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