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ClionApplication · Jetbrains

CVE-2021-45977

CRITICAL · 9.8 CVSS v3.1 Published 2022-02-25
Mitigation only
No fix yet — a mitigation exists. There is no fixed release. A documented workaround reduces exposure in the meantime.
See remediation →
100/100
Remediation priority · Urgent
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
JetBrains IntelliJ IDEA 2021.3.1 Preview, IntelliJ IDEA 2021.3.1 RC, PyCharm Professional 2021.3.1 RC, GoLand 2021.3.1, PhpStorm 2021.3.1 Preview, PhpStorm 2021.3.1 RC, RubyMine 2021.3.1 Preview, RubyMine 2021.3.1 RC, CLion 2021.3.1, WebStorm 2021.3.1 Preview, and WebStorm 2021.3.1 RC (used as Remote Development backend IDEs) bind to the 0.0.0.0 IP address. The fixed versions are: IntelliJ IDEA 2021.3.1, PyCharm Professional 2021.3.1, GoLand 2021.3.2, PhpStorm 2021.3.1 (213.6461.83), RubyMine 2021.3.1, CLion 2021.3.2, and WebStorm 2021.3.1.

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

Multiple JetBrains IDEs (IntelliJ IDEA, PyCharm Professional, GoLand, PhpStorm, RubyMine, CLion, WebStorm) used as Remote Development backends bind to 0.0.0.0 instead of localhost, exposing the IDE's network services to all network interfaces. This allows unauthenticated remote attackers to access the IDE from any network source.

MitigationUpdate to the fixed versions (IntelliJ IDEA 2021.3.1, PyCharm Professional 2021.3.1, GoLand 2021.3.2, PhpStorm 2021.3.1 (213.6461.83), RubyMine 2021.3.1, CLion 2021.3.2, WebStorm 2021.3.1) or implement network access controls/firewall rules to restrict access to the IDE services.

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
ClionApplication
Affected:= 2021.3.1
GolandApplication
Affected:= 2021.3.1
Intellij IdeaApplication
Affected:= 2021.3.1
PhpstormApplication
Affected:= 2021.3.1
PycharmApplication
Affected:= 2021.3.1
RubymineApplication
Affected:= 2021.3.1
WebstormApplication
Affected:= 2021.3.1

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
High
Integrity
High
Availability
High

CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/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. Identify installed JetBrains IDE version
    Open the IDE and go to Help > About, or check the application metadata. For command line, run: ls -la /opt/JetBrains/<ProductName> or on Windows check Program Files/JetBrains/<ProductName>
    Affected if The installed version matches 2021.3.1 for any of: Clion, Goland, IntelliJ Idea, Phpstorm, Pycharm, Rubymine, or Webstorm
  2. Determine if Remote Development mode is active
    Look for running JetBrains Gateway client, remote backend processes, or check for IDE backend services listening on network ports (typically 63342-63399 range). On Linux, run: netstat -tlnp | grep -i jetbrains or ss -tlnp | grep -i jetbrains
    Affected if The IDE is configured to act as a Remote Development backend and is actively running as such
  3. Verify network binding address
    Use netstat or ss to inspect which address the IDE backend service is listening on. Run: netstat -tlnp (Linux) or netstat -an (Windows) and look for the IDE process listening on 0.0.0.0 rather than 127.0.0.1
    Affected if The IDE backend service is bound to 0.0.0.0, making it accessible from all network interfaces rather than localhost only

A user is affected if they are running any of the listed JetBrains IDEs at version 2021.3.1 with Remote Development/Gateway backend enabled, and the service is exposed on 0.0.0.0 instead of 127.0.0.1.

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.

dbcve · scoped
Mitigation available No clean upgrade yet — mitigate in the meantime
Mitigation

Update to the fixed versions (IntelliJ IDEA 2021.3.1, PyCharm Professional 2021.3.1, GoLand 2021.3.2, PhpStorm 2021.3.1 (213.6461.83), RubyMine 2021.3.1, CLion 2021.3.2, WebStorm 2021.3.1) or implement network access controls/firewall rules to restrict access to the IDE services.

Recommended fix High confidence

GoLand 2021.3.2, CLion 2021.3.2, or full 2021.3.1 release for other IDEs (not RC/Preview)

  1. 1. Open your JetBrains IDE (IntelliJ IDEA, PyCharm Professional, GoLand, PhpStorm, RubyMine, CLion, or WebStorm)
  2. 2. Go to Help > About to check your current version (if it shows 2021.3.1 RC, Preview, or 2021.3.1 with older build number, you are affected)
  3. 3. Download the fixed version for your specific IDE from jetbrains.com: GoLand 2021.3.2, CLion 2021.3.2, or the full 2021.3.1 release (not RC/Preview) for IntelliJ IDEA, PyCharm Professional, PhpStorm, RubyMine, or WebStorm
  4. 4. For PhpStorm specifically, ensure build number 213.6461.83 or later
  5. 5. Install the fixed version and restart the IDE

Generated from the published advisory — verify against the referenced sources before acting.

Fix this in Clion Scoped from the published advisory
  • Consultation2.0 h
  • Implementation1.0 h
  • Testing1.0 h
  • Review / QA1.0 h
5.0 hours of engineering $910
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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-2021-45977 in production — separate from our analysis above.

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What this is

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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