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Fencer Vulns
high 7.0

CVE-2018-12029 json

Phusion Passenger Race Condition Allows Privilege Escalation

published 2018-06-17 8 y ago modified 2026-06-17 4 mo ago also GHSA-jjcj-fgfm-9g9r , EUVD-2022-4382

cvss
7.0
version 3.0, NVD
cisa kev
Not listed
not in CISA's catalog
epss
0.3%
EPSS 0.3% chance of exploitation in 30 days, percentile 19%
public exploits
0
none known

Summary

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.

Patch / fix

  • rubygems passenger 5.3.2
  • phusion passenger 5.3.2
  • passenger Debian 14, Debian 13, Debian 12 5.0.30-1.1

debian advisories DEBIAN-CVE-2018-12029

  • passenger Ubuntu 18.04 LTS 5.0.30-1+deb9u1build0.18.04.1
  • passenger Ubuntu Pro 16.04 LTS 5.0.27-2ubuntu0.1~esm1

ubuntu advisories UBUNTU-CVE-2018-12029

Ubuntu security data © Canonical Ltd., from https://github.com/canonical/ubuntu-security-notices via OSV; changed: normalised to fixed package versions per release. CC BY-SA 4.0

  • rubygem-passenger SLE Module for Containers 12 5.0.18-12.9.1

suse advisories SUSE-SU-2018:2039-1

Vendor advisories

What the vendors themselves say about their products: affected, fixed or not affected, and what to do.

red hat product security vex CVE-2018-12029 updated cvss 7.8

passenger: CHMOD race condition in nginx_module/ngx_http_passenger_module.c allows for local privilege escalation

  • Red Hat Ceph Storage 1.3 rubygem-passenger
    affected: no fix planned “Will not fix”
  • Red Hat Satellite 6 mod_passenger, rubygem-passenger, rubygem-passenger-native, rubygem-passenger-native-libs Red Hat Update Infrastructure 3 for Cloud Providers rubygem-passenger
    not affected: vulnerable code not present

Red Hat CSAF VEX © Red Hat, Inc., from https://security.access.redhat.com/data/csaf/v2/vex/; changed: reduced to product statuses and remediations. CC BY 4.0 · csaf

Exploit prediction

0.27% chance of exploitation in the next 30 days, higher than 19% of all scored CVEs (FIRST EPSS, 2026-11-08).

CVSS scores

assigned by version score vector
NVD 3.0 7.0 CVSS:3.0/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H
NVD 2.0 4.4 AV:L/AC:M/Au:N/C:P/I:P/A:P
GitHub 3.0 7.0 CVSS:3.0/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H

Affected packages

ecosystem package affected fixed in
rubygems passenger
>=3.0.0, <5.3.2
5.3.2

Classification

Weakness
  • CWE-362 Concurrent Execution using Shared Resource with Improper Synchronization

References

Sources

Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.