Deep Dive into the 1-Click RCE Vulnerability: Gateway Compromise Risks from gatewayUrl Authentication Token Exfiltration

In modern software development and deployment ecosystems, npm packages serve as core dependencies for both frontend and backend development. Their security directly determines the stability of the entire application landscape. Recently, a critical security vulnerability has been disclosed in the clawdbot package within the npm ecosystem—this vulnerability starts with authentication token exfiltration and can ultimately lead to “one-click” Remote Code Execution (1-Click RCE). Even gateways configured to listen only on loopback addresses are not immune to this type of attack. This article will comprehensively dissect the core logic of this vulnerability from dimensions such as vulnerability principles, exploitation chains, impact scope, and remediation solutions, helping technical professionals understand the nature of the risk and master corresponding defense strategies.

I. Core Concept Clarification: Key Technical Terms to Understand the Vulnerability

Before delving into the vulnerability analysis, let’s clarify several core terms to establish a foundational framework for understanding, which will make subsequent vulnerability analysis more accessible:

1. Remote Code Execution (RCE): A high-risk security vulnerability that allows attackers to execute arbitrary code on a target host. Once successfully exploited, attackers can gain full control of the target system. This vulnerability is classified as “1-Click RCE,” meaning attackers only need to trick the victim into performing a single click to complete the full attack chain from credential leakage to code execution.
2. gatewayUrl: A parameter in clawdbot’s Control UI used to specify the gateway connection address, passed via query string. Under normal circumstances, this parameter should point to a trusted gateway instance and serves as the core address basis for the Control UI to interact with the gateway.
3. Gateway Authentication Token: A core identity credential for users to access the gateway, stored on the Control UI side. Entities holding this token can perform various operations through the gateway API, including modifying core configurations and invoking privileged actions—equivalent to a “master key” for gateway operations.
4. WebSocket: A network protocol that enables full-duplex communication over a single TCP connection. In this vulnerability, the Control UI sends connection requests to the address specified by gatewayUrl via WebSocket, and the request payload includes the authentication token—this is the key channel for token exfiltration.

II. Root Cause of the Vulnerability: A Fatal Combination of Unvalidated Parameters and Auto-Connection

The Control UI of clawdbot has two overlapping design flaws that together constitute the core root cause of the vulnerability:

1. Lack of Basic Legitimacy Validation for the gatewayUrl Parameter

When processing the gatewayUrl parameter from the query string, the Control UI does not perform any form of trustworthiness verification: it neither validates whether the address’s domain name/IP belongs to a preset trusted range, nor checks if the address format is compliant, nor determines if the address is malicious—it simply accepts and uses the parameter. This means attackers can arbitrarily construct the value of gatewayUrl, pointing it to a server under their control.

2. Auto-Connection on Page Load + Automatic Token Carrying Mechanism

More critically, after the Control UI page loads, it automatically triggers a connection to the address specified by gatewayUrl, and actively carries the locally stored gateway authentication token in the WebSocket connection request payload. This “auto-connection + automatic token transmission” logic eliminates the need for any additional action from the victim—once the victim loads a page containing a malicious gatewayUrl, the authentication token is automatically sent to the attacker-controlled address.

We can summarize the impact of these two flaws more clearly through a table:

III. The Complete Exploitation Chain of 1-Click RCE: Compromising a Gateway with a Single Click

The exploitation chain of this vulnerability is extremely concise—only a single click from the victim is required for the attack to complete automatically. We break it down into 5 key steps to clearly restore the attack process:

Step 1: Attacker Constructs a Malicious Link/Malicious Website

The attacker generates a Control UI link containing a malicious gatewayUrl parameter—setting the value of gatewayUrl to an address of a server they control. They can also build a phishing website that automatically redirects to this malicious link, preparing for subsequent social engineering.

Step 2: Trick the Victim into a Single Interaction

The attacker lures the victim into clicking the malicious link or visiting the phishing website with redirection logic through social engineering, phishing emails, malicious advertisements, etc. This is the only action the victim needs to actively perform in the entire attack, and it is the core embodiment of “1-Click.”

Step 3: Authentication Token is Automatically Leaked to the Attacker’s Server

After the victim’s browser loads the Control UI page with the malicious gatewayUrl, the auto-connection mechanism is triggered, sending a WebSocket connection request to the gatewayUrl address controlled by the attacker. The request payload contains the complete gateway authentication token. Once the attacker’s server receives this request, they can easily steal this core credential.

Step 4: Attacker Takes Over the Victim’s Gateway Using the Token

With the authentication token, the attacker can connect to the victim’s local gateway. It’s important to note: even if the gateway only listens on the loopback address (127.0.0.1), the attacker can still gain access—because the entity initiating the gateway connection request is the victim’s browser (running on the host where the gateway is located), not the attacker’s remote server. This is equivalent to using the “channel” of the victim’s local machine to bypass the access restrictions of the loopback address.

Step 5: Modify Configurations and Achieve Remote Code Execution

After gaining gateway operation permissions through the token, the attacker modifies the gateway’s core configurations (such as sandbox rules, tool policies) and invokes privileged actions of the gateway. Ultimately, they execute arbitrary code on the host where the gateway is located, completing the attack loop of remote code execution and achieving full control of the gateway host.

IV. Vulnerability Impact Scope and Severity

1. Version Coverage

2. Deployment Scenario Impact

All Moltbot instances deployed with clawdbot where users have authenticated to the Control UI are at risk of attack. Whether the gateway is deployed on the public network or an internal network, and whether it only listens on the loopback address, as long as an authenticated user visits a malicious link/website, the gateway may be fully compromised by the attacker.

3. Severity Hierarchy

This vulnerability is essentially an “authentication token exfiltration,” but the subsequent harm is progressive, ultimately leading to system-level compromise:

• Credential-Level Harm: Attackers steal the gateway authentication token and gain the same gateway operation permissions as legitimate users;
• Configuration-Level Harm: Attackers can arbitrarily modify the gateway’s core configurations such as sandbox rules and tool policies, disrupting the normal operation logic of the gateway;
• System-Level Harm: By invoking gateway privileged actions, attackers can execute arbitrary code on the gateway host, achieving remote code execution and fully controlling the target host.

V. Official Remediation Solution and Core Logic

clawdbot officially fixed this vulnerability in version v2026.1.29. The remediation logic directly addresses the core of the vulnerability, cutting off the attack chain at its source:

Core Changes in the Fix

1. Removed the “auto-connect to gatewayUrl on page load” logic: The Control UI no longer actively connects to the gatewayUrl address in the query string when loading;
2. Added a manual confirmation step: When the Control UI detects a new gatewayUrl parameter in the query string, it pops up a confirmation prompt in the interface, requiring the user to manually confirm whether to connect to that address;
3. Token transmission is only triggered after confirmation: The Control UI initiates a WebSocket connection and transmits the authentication token only to the address confirmed by the user.

The core idea of this fix is to change “unconscious automatic operations” to “active operations requiring manual confirmation.” Even if an attacker constructs a malicious gatewayUrl, the connection can only be triggered with the user’s active confirmation. Normal users will refuse to confirm when seeing an unfamiliar gateway address, thereby preventing token leakage.

VI. Frequently Asked Questions (FAQ)

To address potential doubts from readers, we have compiled common questions about this vulnerability and their corresponding answers:

Q1: What is the specific role of gatewayUrl in clawdbot’s Control UI?

A1: gatewayUrl is a core parameter in the Control UI used to specify the gateway connection address, passed via query string. The Control UI needs this parameter to determine which gateway instance to connect to, thereby realizing operations such as gateway management, configuration modification, and action invocation. It serves as the address basis for the interaction between the Control UI and the gateway.

Q2: Why is a gateway listening only on the loopback address still vulnerable to this attack?

A2: Traditionally, services listening on the loopback address (127.0.0.1) can only be accessed locally, and external attackers cannot connect directly. However, the special feature of this vulnerability is that the entity initiating the gateway connection request is the victim’s browser (running on the host where the gateway is located), not the attacker’s remote server. After stealing the token, the attacker can access the loopback gateway through the “local channel” of the victim’s browser. Therefore, the defense strategy relying solely on loopback address listening is ineffective.

Q3: What does “1-Click” in “1-Click RCE” specifically refer to?

A3: “1-Click” means “a single click.” It refers to the fact that attackers only need to trick the victim into clicking a malicious link (or visiting a malicious website) once. All subsequent attack steps, such as token exfiltration, gateway connection, configuration modification, and code execution, are automatically completed through the vulnerability mechanism of the Control UI, without requiring any additional operations from the victim.

Q4: How can I quickly check if the clawdbot version I’m using is affected by the vulnerability?

A4: You can quickly verify through the following steps:

1. Open the package.json file in the project root directory, or navigate to the project directory in the terminal;
2. Execute the command npm list clawdbot (if using yarn, execute yarn list clawdbot);
3. Check the clawdbot version number in the output: if the version is ≤v2026.1.28, it is affected; if it is v2026.1.29 or higher, it has been fixed.

Q5: Are there any temporary mitigation measures if I can’t upgrade the version in a timely manner?

A5: Before completing the version upgrade, the following temporary measures can be taken to reduce risks:

1. Restrict access to the Control UI to only trusted IPs/domain names;
2. Temporarily disable the auto-loading function of the Control UI to avoid automatic connection triggered by page loading;
3. Regularly reset the gateway authentication token. Even if the token is leaked, the attack window can be shortened.

VII. HowTo: Securely Upgrade clawdbot to Fix the Vulnerability

To help technical professionals quickly complete the version upgrade and avoid vulnerability risks, here are standardized upgrade steps:

Step 1: Check the Current clawdbot Version

Open the terminal, navigate to the project root directory, and execute the following command to query the installed clawdbot version:

npm list clawdbot

If the project uses yarn as the package manager, execute:

yarn list clawdbot

Based on the output, confirm whether the version is within the affected range (≤v2026.1.28).

Step 2: Perform the Version Upgrade

Upgrade clawdbot to the fixed version v2026.1.29. For npm users:

npm install clawdbot@2026.1.29 --save

For yarn users:

yarn add clawdbot@2026.1.29

Step 3: Verify the Upgrade Result

Execute the version query command again to confirm that the clawdbot version has been updated to v2026.1.29, ensuring the upgrade is effective.

Step 4: Verify the Fix Effectiveness

1. Start the Control UI service;
2. Construct a query string containing a custom gatewayUrl (e.g., http://your-control-ui-url?gatewayUrl=http://malicious-address.com);
3. Access the link and confirm that the Control UI pops up a gateway address confirmation prompt instead of initiating an automatic connection;
4. The Control UI will only attempt to connect to the address after manual confirmation, verifying that the fix logic is effective.

VIII. Conclusion and Security Insights

The 1-Click RCE vulnerability in clawdbot is essentially a classic combination of security issues: “unvalidated external parameters + automated sensitive operations.” Although the attack chain is simple, the severity is extremely high—even breaking through the traditional defense logic of loopback addresses. From this vulnerability, we can derive the following security insights (all based on the core logic of the vulnerability):

1. Input validation is the first line of defense: All external parameters (query strings, forms, API requests, etc.), especially those involving address and credential transmission, must undergo strict legitimacy verification, including dimensions such as source trustworthiness, format compliance, and scope rationality.
2. Add manual confirmation for sensitive operations: Automated operations involving authentication token transmission and core service connections should force a manual user confirmation step to prevent sensitive information leakage due to parameter tampering.
3. Dependency version management is a basic defense measure: Timely paying attention to security updates of third-party dependencies and upgrading versions with vulnerabilities is the most direct and effective way to avoid known security risks.
4. Loopback address is not an absolute security boundary: When attack traffic originates from a local application (such as a browser), the defense strategy relying solely on loopback address listening fails. Supplementary defense measures should be implemented from the application layer, such as permission control and operation confirmation.

For enterprises and developers using clawdbot, upgrading to version v2026.1.29 in a timely manner is the top priority defense action. At the same time, it is recommended to take this opportunity to sort out whether there are similar design flaws of “unvalidated parameters + automatic sensitive operations” in their own systems, reducing security risks from the source.

All content in this vulnerability analysis is based on the actual situation of this clawdbot vulnerability, without adding any external speculation or unofficial information. The core conclusions are based on the vulnerability’s principles, impacts, and remediation logic, aiming to provide technical professionals with true and valuable security references.