The original author must then react to the comment

Oct 13, 2025 by talynt.org 141 views

Deployment Confirmation: Enhancing Security and Control in GitHub Actions

Introduction

In the realm of software development, security and control are paramount. GitHub Actions, a powerful tool for automating workflows, has become an essential part of many development teams' arsenals. However, with great power comes great responsibility, and one potential vulnerability that has been identified is the TOCTOU (Time of Check to Time of Use) vulnerability in issue_comment triggers. In this article, we will explore a proposed solution to mitigate this risk: deployment confirmation.

The Problem: TOCTOU Vulnerability

The TOCTOU vulnerability arises when a system checks the state of a resource at one point in time, but then uses that resource at a later point in time. In the context of GitHub Actions, this can occur when a user types .deploy and the branch-deploy Action kicks off. The Action determines the commit SHA that is going to be deployed, comments back on the PR with the commit SHA, and then waits for the original author to react to the comment. If the user does not react in a timely manner, the deployment is rejected and cancelled.

However, this process can be vulnerable to TOCTOU attacks, where an attacker could manipulate the commit SHA between the time it is checked and the time it is used. This could potentially lead to a malicious deployment being executed.

The Solution: Deployment Confirmation

To mitigate this risk, we propose implementing a deployment confirmation feature. This feature would prompt the user for confirmation after they type .deploy. The confirmation would be an optional setting that one must enable if they wish to use this feature.

Here is a high-level overview of how the deployment confirmation feature would work:

User types .deploy: The user initiates the deployment process by typing .deploy in the GitHub Actions interface.
The branch-deploy Action kicks off: The branch-deploy Action is triggered, which determines the commit SHA that is going to be deployed.
The branch-deploy Action comments back on the PR with the commit SHA: The Action comments back on the PR with the commit SHA that will be used for the deployment.
The original author must then react to the comment: The original author must then 👍 or 👎 the comment in order for the deployment to continue.
If the user does not react to the comment in a certain timeframe, the deployment is rejected and cancelled: If the user does not react to the comment within a certain timeframe, the deployment is rejected and cancelled.

Benefits of Deployment Confirmation

The deployment confirmation feature offers several benefits, including:

Enhanced security: By requiring user confirmation, we can mitigate the risk of TOCTOU attacks and ensure that deployments are executed with the correct commit SHA.
Improved control: The deployment confirmation feature provides an additional layer of control, allowing users to review and approve deployments before they are executed.
Reduced risk of errors: By requiring user confirmation, we can reduce the risk of errors and ensure that deployments are executed correctly.

Implementation

To implement the deployment confirmation feature, we would need to make the following changes:

Add a new setting: We would need to add a new setting that allows users to enable or disable the deployment confirmation feature.
Modify the branch-deploy Action: We would need to modify the branch-deploy Action to include the deployment confirmation feature.
Add a new comment: We would need to add a new comment to the PR that includes the commit SHA and a prompt for the user to react to the comment.

Conclusion

In conclusion, the deployment confirmation feature is a proposed solution to mitigate the risk of TOCTOU attacks in GitHub Actions. By requiring user confirmation, we can enhance security, improve control, and reduce the risk of errors. We believe that this feature is essential for any development team that uses GitHub Actions and we look forward to implementing it in the near future.

Future Work

There are several areas where we can improve the deployment confirmation feature, including:

Adding more granular controls: We could add more granular controls, such as allowing users to specify a custom timeframe for the deployment confirmation.
Improving the user experience: We could improve the user experience by making the deployment confirmation feature more intuitive and user-friendly.
Adding more features: We could add more features, such as allowing users to specify a custom message for the deployment confirmation.

Recommendations

We recommend that all development teams that use GitHub Actions consider implementing the deployment confirmation feature. This feature is essential for ensuring the security and control of deployments and we believe that it is a must-have for any development team.

Conclusion

Introduction

In our previous article, we discussed the deployment confirmation feature, a proposed solution to mitigate the risk of TOCTOU attacks in GitHub Actions. In this article, we will answer some of the most frequently asked questions about the deployment confirmation feature.

Q: What is the deployment confirmation feature?

A: The deployment confirmation feature is a proposed solution to mitigate the risk of TOCTOU attacks in GitHub Actions. It requires user confirmation after a user types .deploy and the branch-deploy Action kicks off.

Q: Why do we need the deployment confirmation feature?

A: We need the deployment confirmation feature to mitigate the risk of TOCTOU attacks in GitHub Actions. TOCTOU attacks can occur when a system checks the state of a resource at one point in time, but then uses that resource at a later point in time. The deployment confirmation feature ensures that the user confirms the deployment before it is executed.

Q: How does the deployment confirmation feature work?

A: The deployment confirmation feature works as follows:

User types .deploy: The user initiates the deployment process by typing .deploy in the GitHub Actions interface.
The branch-deploy Action kicks off: The branch-deploy Action is triggered, which determines the commit SHA that is going to be deployed.
The branch-deploy Action comments back on the PR with the commit SHA: The Action comments back on the PR with the commit SHA that will be used for the deployment.
The original author must then react to the comment: The original author must then 👍 or 👎 the comment in order for the deployment to continue.
If the user does not react to the comment in a certain timeframe, the deployment is rejected and cancelled: If the user does not react to the comment within a certain timeframe, the deployment is rejected and cancelled.

Q: Is the deployment confirmation feature optional?

A: Yes, the deployment confirmation feature is optional. Users can enable or disable the feature as they see fit.

Q: Can I customize the deployment confirmation feature?

A: Yes, you can customize the deployment confirmation feature. You can specify a custom timeframe for the deployment confirmation and add a custom message for the deployment confirmation.

Q: How does the deployment confirmation feature improve security?

A: The deployment confirmation feature improves security by requiring user confirmation before a deployment is executed. This ensures that the user is aware of the deployment and has the opportunity to review and approve it before it is executed.

Q: How does the deployment confirmation feature improve control?

A: The deployment confirmation feature improves control by providing an additional layer of control for users. Users can review and approve deployments before they are executed, ensuring that the deployment is executed correctly.

Q: Can I use the deployment confirmation feature with other GitHub Actions?

A: Yes, you can use the deployment confirmation feature with other GitHub Actions. The feature is designed to be flexible and can be used with a variety of GitHub Actions.

Q: Is the deployment confirmation feature available now?

A: No, the deployment confirmation feature is not available now. However, we are working on implementing the feature and expect it to be available soon.

Conclusion

Frequently Asked Questions

Q: What is the deployment confirmation feature? A: The deployment confirmation feature is a proposed solution to mitigate the risk of TOCTOU attacks in GitHub Actions.
Q: Why do we need the deployment confirmation feature? A: We need the deployment confirmation feature to mitigate the risk of TOCTOU attacks in GitHub Actions.
Q: How does the deployment confirmation feature work? A: The deployment confirmation feature works by requiring user confirmation after a user types .deploy and the branch-deploy Action kicks off.
Q: Is the deployment confirmation feature optional? A: Yes, the deployment confirmation feature is optional.
Q: Can I customize the deployment confirmation feature? A: Yes, you can customize the deployment confirmation feature.
Q: How does the deployment confirmation feature improve security? A: The deployment confirmation feature improves security by requiring user confirmation before a deployment is executed.
Q: How does the deployment confirmation feature improve control? A: The deployment confirmation feature improves control by providing an additional layer of control for users.
Q: Can I use the deployment confirmation feature with other GitHub Actions? A: Yes, you can use the deployment confirmation feature with other GitHub Actions.
Q: Is the deployment confirmation feature available now? A: No, the deployment confirmation feature is not available now.