CVE-2018-12029: Passenger Phusion Passenger Race Condition Allows Vulnerability

HIGH
Advisory Identifier: GHSA-jjcj-fgfm-9g9r
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CVSS 7.0
CWE-362
Published
Advisory Summary

CVE-2018-12029 is a HIGH (CVSS 7.0) phusion passenger race condition allows vulnerability (CWE-362: Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')) affecting Passenger libraries in the RubyGems ecosystem. The issue involves phusion passenger race condition allows privilege escalation. Remediation is available by upgrading affected packages to version 5.3.2.

CVE-2018-12029 at a Glance

CVE Identifier CVE-2018-12029
GHSA Identifier GHSA-jjcj-fgfm-9g9r
Severity HIGH
CVSS v3.1 Base Score 7.0
CWE Classification CWE-362: Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition')
Affected Product Passenger
Package Ecosystem RubyGems
Published Date
Last Updated

Security Impact

CVSS: 7.0

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.0/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H).

Attack Vector Local (AV:L)
Attack Complexity High (AC:H)
Privileges Required Low (PR:L)
User Interaction None (UI:N)
Scope Unchanged (S:U)
Confidentiality High (C:H)
Integrity High (I:H)
Availability High (A:H)

How to Fix CVE-2018-12029

To remediate this vulnerability, upgrade all affected Passenger dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

passenger fixed: 5.3.2 
Upgrade passenger to 5.3.2
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release: 

inspect dependencies for passenger

How to Check if You Are Affected

To determine whether your application is affected by CVE-2018-12029, inspect your project dependencies for Passenger:

inspect dependencies for passenger

Analyze the terminal output to locate any version of Passenger in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 5.3.2), your application is affected.

Note: Verify declared build manifests and deployed runtime container environments.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-362: Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition'), where the product contains a concurrent code sequence that requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence operating concurrently. In Passenger, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

A race condition in the nginx module in Phusion Passenger 3.x through 5.x before 5.3.2 allows local escalation of privileges when a non-standard passenger_instance_registry_dir with insufficiently strict permissions is configured. Replacing a file with a symlink after the file was created, but before it was chowned, leads to the target of the link being chowned via the path. Targeting sensitive files such as root's crontab file allows privilege escalation.

CVE-2018-12029 Affected Passenger Versions

1 component(s)
Fixed Versions:
5.3.2
Product / Package Ecosystem Affected Versions Fixed Version
passenger
gem/passenger
RubyGems
≥ 3.0.0
< 5.3.2
5.3.2

References

NVD — CVE-2018-12029 NVD
https://nvd.nist.gov/vuln/detail/CVE-2018-12029
Passenger Security Information SECURITY
https://blog.phusion.nl/2018/06/12/passenger-5-3-2-various-security-fixes
blog.phusion.nl/passenger-5-3-2 WEB
https://blog.phusion.nl/passenger-5-3-2
Passenger Source Repository REPOSITORY
https://github.com/rubysec/ruby-advisory-db/blob/master/gems/passenger/CVE-2018-12029.yml
lists.debian.org/debian-lts-announce... WEB
https://lists.debian.org/debian-lts-announce/2018/06/msg00007.html
Passenger Security Information SECURITY
https://pulsesecurity.co.nz/advisories/phusion-passenger-priv-esc
Passenger Security Information SECURITY
https://security.gentoo.org/glsa/201807-02

Frequently Asked Questions

What is CVE-2018-12029?
CVE-2018-12029 is a security vulnerability in Passenger involving Phusion Passenger Race Condition Allows Privilege Escalation under CWE-362: Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition').
Which Passenger versions are affected?
Affected versions include releases prior to 5.3.2 across affected packages: passenger.
What version fixes CVE-2018-12029?
Upgrading to 5.3.2 (or the latest patched release for your respective branch) resolves the vulnerability.
Is passenger affected?
Yes, passenger is affected in releases prior to 5.3.2. Upgrade your dependency to 5.3.2 or later.
What is the CVSS score of CVE-2018-12029?
CVE-2018-12029 has a CVSS v3.1 base score of 7.0 (HIGH) with vector string CVSS:3.0/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H.
What CWE is associated with CVE-2018-12029?
CVE-2018-12029 is classified under CWE-362: Concurrent Execution using Shared Resource with Improper Synchronization ('Race Condition') (The product contains a concurrent code sequence that requires temporary, exclusive access to a shared resource, but a timing window exists in which the shared resource can be modified by another code sequence operating concurrently.).
How can I check RubyGems dependencies for CVE-2018-12029?
Run the dependency tree command: 'inspect dependencies for passenger'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
View Raw JSON 
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-jjcj-fgfm-9g9r",
  "modified" : "2023-07-03T21:46:30Z",
  "published" : "2022-05-14T01:27:14Z",
  "aliases" : [ "CVE-2018-12029" ],
  "summary" : "Phusion Passenger Race Condition Allows Privilege Escalation",
  "details" : "A race condition in the nginx module in Phusion Passenger 3.x through 5.x before 5.3.2 allows local escalation of privileges when a non-standard passenger_instance_registry_dir with insufficiently strict permissions is configured. Replacing a file with a symlink after the file was created, but before it was chowned, leads to the target of the link being chowned via the path. Targeting sensitive files such as root's crontab file allows privilege escalation.",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.0/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "RubyGems",
      "name" : "passenger"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "3.0.0"
      }, {
        "fixed" : "5.3.2"
      } ]
    } ]
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2018-12029"
  }, {
    "type" : "WEB",
    "url" : "https://blog.phusion.nl/2018/06/12/passenger-5-3-2-various-security-fixes"
  }, {
    "type" : "WEB",
    "url" : "https://blog.phusion.nl/passenger-5-3-2"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/rubysec/ruby-advisory-db/blob/master/gems/passenger/CVE-2018-12029.yml"
  }, {
    "type" : "WEB",
    "url" : "https://lists.debian.org/debian-lts-announce/2018/06/msg00007.html"
  }, {
    "type" : "WEB",
    "url" : "https://pulsesecurity.co.nz/advisories/phusion-passenger-priv-esc"
  }, {
    "type" : "WEB",
    "url" : "https://security.gentoo.org/glsa/201807-02"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-362" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2023-06-09T23:01:12Z",
    "nvd_published_at" : "2018-06-17T20:29:00Z"
  }
}