Feedback wanted:

Discontinuing the Burp Suite JAR to improve security and performance

We're considering removing the option to download each version of Burp Suite as a standalone JAR file. We're aware that some users may be impacted by this change. To ensure that you have a chance to share any concerns, we're reaching out to those who we think may be affected.

We'll explore the reasons why we're looking into this and explain why you might not need to use the JAR after all. We'll also share workarounds for common JAR use cases, including how to deploy a private Collaborator server.

Finally, we'd like to give you the opportunity to share your thoughts on whether this will work for you so that we can take steps to mitigate the impact this might have.

Why are we considering this change?

The following are some of the key reasons why we're considering removing the JAR option from the website.

Exposure through missed security updates

As every security professional knows, timely updates are crucial for application security. Without them, users run the risk of attackers using known vulnerabilities to exploit them.

In particular, Burp's embedded Chromium browser represents a significant attack surface and frequently needs critical security updates. That's why we aim to include the most recent stable version of Chromium with each release of Burp, and even fast-track releases just to update Chromium when necessary.

While analyzing the versions of Burp Suite in active use, we noticed that the majority of versions with unpatched vulnerabilities were running Burp from a JAR. We suspect that this is largely due to the JAR version lacking the auto-update functionality, meaning you have to manually download a new JAR every time we release.

If you use one of the standard, package-based installations we provide for Linux, macOS, and Windows respectively, you benefit from auto-updates, ensuring that you never miss a security patch.

Use of insecure, outdated runtime environments

Our platform-specific installations include their own Java Runtime Environment (JRE).

If you run Burp from a JAR file, you need to maintain your own environment, which in practice means that many JAR users are relying on older JREs. Not only is this a common source of bugs and performance issues - a topic that we know is close to your heart - it introduces another security weakness as you may be exposed to known vulnerabilities in outdated JRE versions.

Just like Burp Suite itself, if you use one of the platform-specific installers and auto-updates, we keep the JRE up to date on your behalf, ensuring the most stable and secure experience.

Bloated file size

In addition to potential security and performance issues, the JAR file also takes up excessive disk space. Although the app itself runs on the platform-agnostic JVM, the built-in Chromium browser is platform-specific, meaning the all-in-one JAR download contains three entire browsers, one for each OS.

Our platform-specific installers are much leaner by comparison, and only contain what's necessary for your environment.

Customizing JVM settings without the JAR

Users often run Burp from a JAR so that they have more granular control of the JVM. If this applies to you, the good news is that you can still do this with our installer-based versions of Burp.

Some options that were previously only available as command-line arguments, such as being able to specify how much memory is allocated to the JVM, you can now control from the regular settings menu (Settings > Suite > Startup behavior > Maximum Java memory usage).

Alternatively, you can pass all of the same arguments to the JVM by creating an options file in the installation directory. To do this:

Either download the relevant Burp Suite installer and run it, or go to your existing Burp Suite installation directory. By default, you can find this in the following location:
- Linux:/home/<user>/BurpSuite
- macOS:/Users/<user>/Applications/Burp Suite Professional
- Windows:C:\Program Files\BurpSuitePro
In the installation directory, locate the JAR file.
In the same directory as the JAR, create a file called user.vmoptions
In the user.vmoptions file, list all of the arguments that you normally pass via the command line, separating each with a newline.

From now on, when you launch the installed version of Burp, it runs on the JVM using your specified configuration.

Example
If you normally run:

java -Xmx4g -Xms128m -Dsun.java2d.uiScale.enable=false -jar /path/to/burp.jar

You can instead just create a user.vmoptions file with the following contents:
-Xmx4g
-Xms128m
-Dsun.java2d.uiScale.enable=false

Note: Do not modify the vmoptions.txt or settings.vmoptions files. These are often overwritten during updates, meaning any changes you make will be lost. We never modify the user.vmoptions file.

What if I still need the JAR?

While the workarounds above remove the need for most people to use the JAR, we're aware that there are some specialist use cases that may be impacted.

If you do still need to use the JAR, for example, to support custom workflows and automation, to help with developing extensions, or to deploy a private Collaborator server, there is a simple workaround - the installation package also contains a JAR that you can use instead.

Using the JAR from a Burp Suite Professional or Community Edition installation

This method provides much of the same flexibility, while leveraging the security and convenience of the installer-based version. This way, you can keep the JAR version up to date by simply launching Burp Suite and letting the auto-update kick in.

Either download the relevant Burp Suite installer and run it, or go to your existing Burp Suite installation directory. By default, you can find this in the following location:
- Linux:/home/<user>/BurpSuite
- macOS:/Users/<user>/Applications/Burp Suite Professional
- Windows:C:\Program Files\BurpSuitePro
In the installation directory, locate the JAR file.
Refactor your existing scripts to point to the new JAR location, or manually invoke the JAR from the command line as you normally would.

Note: Avoid running the JAR from the installation directory while simultaneously running the installed version of Burp Suite as this can cause unexpected behavior. If you want to run both versions concurrently, we recommend copying the JAR to a different location outside of the installation package. However, note that this means you won't benefit from auto-updates to your copy of the JAR file.

Using the JAR from a Burp Suite Enterprise Edition installation

If you are a Burp Suite Enterprise Edition user, you can follow the same process as Burp Suite Professional users. However, if you don't want to or are unable to install Burp Suite Professional, you can also use the JAR file from your Burp Suite Enterprise Edition installation.

From the machine on which your Enterprise server is running, locate the JAR file in the installation directory. By default, you can find this in the following location:
- Linux:/opt/burpsuite_enterprise/burp/burpsuite_pro_<build-number>.jar
- Windows:C:\ProgramFiles\burpsuite_enterprise\burp\burpsuite_pro_<build-number>.jar
Copy the JAR to a different machine or a location outside the installation directory.
Invoke the JAR from the command line as you normally would.

Note: Do not invoke the JAR directly from the installation directory. This can cause unexpected issues if your Burp Suite Enterprise Edition instance is running simultaneously.

Deploying a private Collaborator server

Deploying a private Collaborator server requires you to run Burp from a JAR file using the --collaborator-server command-line flag. If we remove the option to download the JAR from the website, you can still deploy a private Collaborator server using the JAR provided in either the Burp Suite Professional or Burp Suite Enterprise Edition installation package.

Note: This applies to Collaborator servers that you intend to use with either Burp Suite Professional or Burp Suite Enterprise Edition.

Locate the JAR from a Burp Suite Professional or Enterprise Edition installation, as described above. If you want to deploy the Collaborator server on a different OS to your existing Burp Suite installation, download and run the relevant Burp Suite Professional installer.
Copy the JAR to the machine on which you want to run the Collaborator server.
(Optional) If you ran the installer purely to extract the JAR, run the uninstaller to remove the leftover files from your system.
Invoke the JAR using the --collaborator-server flag as you normally would. For detailed instructions on the rest of the process, see Deploying a private Collaborator server.