dbcve.org
Intellij IdeaApplication · Jetbrains

CVE-2021-30504

HIGH · 7.5 CVSS v3.1 Published 2021-05-11
Fix available
A fix is available. Upgrade to 2021.1 or later.
See remediation →
84/100
Remediation priority · High
Remotely reachable No privileges Zero-click

Official description Straight from the sourceThe vendor's or NVD's own wording, published unedited. Authoritative, but often terse — it says what broke, rarely what to do.

NVD · unedited
In JetBrains IntelliJ IDEA before 2021.1, DoS was possible because of unbounded resource allocation.

Technical summary Written by usOur analysis, written from the advisory, the CVSS vector and the affected-version data. It adds context the advisory leaves out, and never invents facts that are not in the source.

dbcve analysis · high confidence

This is a Denial of Service vulnerability in JetBrains IntelliJ IDEA versions prior to 2021.1. The vulnerability stems from unbounded resource allocation (likely memory, CPU, or file handles) that allows an attacker to exhaust system resources and crash the IDE.

MitigationUpgrade to IntelliJ IDEA 2021.1 or later, which implements proper resource allocation limits to prevent resource exhaustion.

Verify against the referenced sources before acting — the references below are authoritative for this CVE, this summary is not.

Affected products & versions What the vendor confirmedThe version ranges the vendor confirmed as vulnerable. If your version sits inside a range here, treat yourself as exposed until you have upgraded.

NVD · CPE data
Intellij IdeaApplication
Affected:< 2021.1

CVSS breakdown How the score is builtThe industry scoring standard. It rates how the flaw is reached, what it takes to exploit, and what an attacker gains — the score is derived from those, not the other way round.

From the vector
Attack vector
Network
Complexity
Low
Privileges
None
User interaction
None
Scope
Unchanged
Confidentiality
None
Integrity
None
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H

Am I affected? How to checkSteps we derive from the advisory and the affected-version data, so you can decide whether this CVE reaches your setup. They are a guide, not a scan — your own configuration is the authority.

dbcve checks

Work through these to decide whether this CVE applies to you.

  1. Check IntelliJ IDEA installed version
    Open IntelliJ IDEA, then go to Help > About (on Windows/Linux) or IntelliJ IDEA > About (on macOS). The version number is displayed in the dialog that appears.
    Affected if The version shown is earlier than 2021.1 (for example, 2020.3, 2020.2, etc.)
  2. Verify version from command line
    Run the IDE and check the build number in the installation directory, or look at the startup log files in the IDEA system directory (typically ~/.IdeaIC{version}/system/log/). The version format is like 211.xxxx for 2021.1.x builds.
    Affected if The build number starts with a value less than 211 (for example, 203.xxxx indicates a 2020.3.x version)
  3. Confirm affected configuration
    This vulnerability is triggered by the IDE processing certain inputs or operations that cause unbounded resource allocation. No specific feature needs to be enabled - the flaw exists in the core IDE processing.
    Affected if Running any version of IntelliJ IDEA prior to 2021.1 makes the IDE vulnerable to this DoS condition

If the installed IntelliJ IDEA version is earlier than 2021.1 (build number below 211), the environment is affected by this resource exhaustion vulnerability.

Generated from the published advisory. Verify against your own configuration.

Check your environment

Paste your version and any relevant configuration and it will be compared against the affected criteria above. Do not include secrets or credentials.

AI-assisted, checked against the advisory. Informational, not a guarantee.

Remediation Closing itWhat it takes to close this. Where a vendor fix exists we point at it; where none exists we say so plainly, and can build one. Effort estimates are scoped from the advisory, not from your codebase.

From vendor data
Upgrade available Upgrade to 2021.1 or later
Fixed in 2021.1
Interim mitigation

Upgrade to IntelliJ IDEA 2021.1 or later, which implements proper resource allocation limits to prevent resource exhaustion.

Fix this in Intellij Idea Scoped from the published advisory
  • Consultation2.0 h
  • Implementation8.0 h
  • Testing4.0 h
  • Review / QA2.0 h
16.0 hours of engineering $2,800
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $4,480.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

Check whether your project pulls in CVE-2021-30504 — or any other known-vulnerable package — straight from your lock files. Free and open source; it runs locally and uploads nothing.

Get it on GitHub Scan in the browser

References Go to the primary sourcePrimary sources — vendor advisories, patches and trackers. Where our summary and a reference disagree, the reference wins.

Primary sources

Practitioner notes

Contributed

Peer-ranked notes from engineers who’ve handled CVE-2021-30504 in production — separate from our analysis above.

No notes yet

Be the first to add a field note for this CVE — a mitigation you’ve verified, a version caveat, or a link to a working fix. Sign in above to contribute.

What this is

A place for practitioners to share what actually worked: a mitigation you’ve tested, a configuration change, a version- or environment-specific caveat, or a link to a verified patch. The most useful notes rise to the top as peers upvote them, so the signal stays high.

What belongs here
  • Verified mitigations, workarounds, and config changes
  • Version or environment caveats, and links to real fixes
  • No weaponised exploit code, or anything meant to cause harm
  • No spam, self-promotion, credentials, or personal data