PassengerApplication · Phusion

CVE-2018-12028

HIGH · 7.8 CVSS v3.0 Published 2018-06-17
Fix available
A fix is available. Upgrade to 5.3.2 or later.
See remediation →
81/100
Remediation priority · High
No privileges

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
An Incorrect Access Control vulnerability in SpawningKit in Phusion Passenger 5.3.x before 5.3.2 allows a Passenger-managed malicious application, upon spawning a child process, to report an arbitrary different PID back to Passenger's process manager. If the malicious application then generates an error, it would cause Passenger's process manager to kill said reported arbitrary PID.

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

In Phusion Passenger's SpawningKit component, a malicious managed application can spoof the PID it reports back to Passenger's process manager. When the application triggers an error, Passenger incorrectly terminates the spoofed PID (which could be an unrelated process) instead of the actual child process.

MitigationUpgrade Phusion Passenger to version 5.3.2 or later to obtain the patched SpawningKit component that validates reported PIDs.

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
PassengerApplication
Affected:>= 5.3.0, < 5.3.2

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
Local
Complexity
Low
Privileges
None
User interaction
Required
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.0/AV:L/AC:L/PR:N/UI:R/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. Find installed Passenger version
    Run `passenger --version` or check via package manager (e.g., `dpkg -l | grep passenger`, `rpm -qa | grep passenger`)
    Affected if Version is displayed as 5.3.0 or 5.3.1 (falls in range >= 5.3.0, < 5.3.2)
  2. Confirm version is in affected range
    Compare the installed version number against the vulnerable range: >= 5.3.0 and < 5.3.2
    Affected if Installed version is 5.3.0 or 5.3.1
  3. Verify SpawningKit is in use
    Check Passenger configuration or inspect spawning method used for managed applications. SpawningKit handles spawning for Ruby, Python, Node.js, and Meteor apps. Look for `PassengerSpawnMethod` directive or app type configuration.
    Affected if Applications are spawned using SpawningKit (default spawn method for most app types)
  4. Check for application control over PID reporting
    Audit managed applications to determine if they have the ability to influence or spoof the PID they report back to the Passenger process manager during spawn errors
    Affected if Untrusted or third-party applications are running as managed Passenger apps and could manipulate PID reporting

Environment is affected if Phusion Passenger version is 5.3.0 or 5.3.1 AND SpawningKit is used to spawn applications that could spoof PIDs.

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 5.3.2 or later
Fixed in 5.3.2
Interim mitigation

Upgrade Phusion Passenger to version 5.3.2 or later to obtain the patched SpawningKit component that validates reported PIDs.

Fix this in Passenger Scoped from the published advisory
  • Consultation2.0 h
  • Implementation2.0 h
  • Testing4.0 h
  • Review / QA2.0 h
10.0 hours of engineering $1,720
Get the upgrade done

An estimate, not a bill — we confirm scope with you before any work starts. Need it this week? Rush from $2,752.

Scan for this in your stack

Free · runs locally
dbcve dependency scanner

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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-2018-12028 in production — separate from our analysis above.

No notes yet

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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