JetBrains IntelliJ IDEA is the go-to IDE for millions of Java developers. With its wide range of plugins, integrating platforms like JetBrains Space becomes a breeze. But in 2023, a not-so-obvious issue crept into the process: the Space plugin in IntelliJ IDEA released before version 2023.2 was asking for more than its fair share of permissions, exposing user data and creating unnecessary security risks.

Let’s dig into what happened, how it could affect you, and what you need to know to stay safe.

What is CVE-2023-39261?

CVE-2023-39261 is a security flaw discovered in JetBrains IntelliJ IDEA (before 2023.2) related to its Space plugin.

In plain English:
When you installed the Space plugin and connected to your company’s Space instance, the plugin asked JetBrains Space for far more permissions than it actually needed—like being able to view, update, and even delete parts of your Space workspace unrelated to its main functionality.

The Excessive Permissions Flaw — Breaking It Down

A plugin might need to fetch project lists or read notifications to do its job. But imagine it also asked to:

* Read your profile details
* Modify chat messages
* Access private repositories
* Change your team settings

That’s what the affected Space plugin did. Due to its “overbroad OAuth scopes” request, if your Space admin or user wasn’t careful, you basically gave the plugin (and anyone controlling it) the keys to parts of your workspace that it should never have.

Here’s a simplified snippet showing what the plugin’s code did when connecting to Space

// BEFORE FIX: Asking for too many permissions
val request = SpaceOAuthRequest(
    scopes = listOf(
        "profile:read",
        "profile:write",
        "projects:read",
        "projects:write",
        "projects:admin",
        "chats:read",
        "chats:write",
        "repos:read",
        "repos:write"
        // and more...
    )
)

Instead, the plugin only really needed "projects:read" and maybe "chats:read".

By requesting all these extra permissions, the following could happen

- Data Overexposure. The plugin could read and modify data well beyond what’s required — including your source code, settings, and private messages.
- Privilege Escalation. If the plugin or a related service got compromised, attackers could exploit these excessive permissions to do much more damage than if the principle of least privilege was followed.
- Compliance and Privacy Issues. Organizations could unknowingly break their own internal policies or regulatory rules by leaking too much user data to the plugin.

Publicly Available Exploit?

No direct exploit code was published as of this writing. However, with the excessive scopes, a malicious or compromised Space plugin could programmatically fetch user data or make changes on behalf of someone—without the user ever knowing.

A simple example in Kotlin pseudocode

// Using granted write permissions to delete a project!
fun deleteProject(spaceApi: SpaceApi, projectId: String) {
    // This should NEVER be possible from a read-only integration!
    spaceApi.projects.delete(projectId)
}

How to Fix and Protect Yourself

* Update IntelliJ IDEA. Make sure you’re using version 2023.2 or later. JetBrains fixed the plugin to only request the minimal permissions needed (see JetBrains Release Notes).
* Revoke Old Plugin Authorizations. Log into Space, go to your profile > Applications, and revoke authorization for “IntelliJ IDEA Space plugin” issued before your update.
* Review Permission Requests. If any plugin or integration asks for broad access, pause and check if that makes sense. Less is always safer.

References

- JetBrains Security Advisory for CVE-2023-39261
- CVE Record on NVD
- How Space OAuth Works (docs)

Conclusion

CVE-2023-39261 wasn’t a flashy, code-execution bug. But the “space” it opened up for abuse was real, affecting privacy and giving plugins too much trust. Always keep IDEs and plugins updated, and be careful of what you approve. Your code—and your team’s secrets—might depend on it.

Timeline

Published on: 07/26/2023 13:15:00 UTC
Last modified on: 08/02/2023 20:34:00 UTC