CVE-2018-12029

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.

Published: 2018-06-17 Last update: 2024-11-21 Assigner: [email protected] Source: [email protected]
NVD Status：Modified，CVE State: published
View at NVD, CVE.org, EUVD

CVE-2018-12029 is rated Low Risk (37.9/100): CVSS High severity, with low exploitation likelihood (EPSS 0.10%). Monitor for updates and reassess as exploit intelligence or EPSS changes.

Risk is dynamic; we continuously reassess and refresh what is shown on this page as upstream context changes.

Exploit prediction scoring system (EPSS) score for CVE-2018-12029

EPSS lead: Daily EPSS estimates relative likelihood of exploitation; percentile ranks this CVE among scored vulnerabilities (higher = more severe relative rank).

# Date Old EPSS score New EPSS score Delta (New - Old)
1 2025-11-21 0.04% 0.10% +0.05%
2 2025-11-18 0.10% 0.04% -0.06%
3 2025-03-17 — 0.10% —

Full EPSS history (6 records total)

Common vulnerability scoring system (CVSS) metrics for CVE-2018-12029

CVSS metrics for this CVE.

Base score Version Severity Vector Exploitability Impact Score source
7.0 3.0 HIGH
CVSS:3.0/AV:L/AC:H/PR:L/UI:N/S:U/C:H/I:H/A:H Click to expand
Attack vector (AV:L)
They already need access on the box, or another person has to do something wrong; it’s not a remote drive-by.
Attack complexity (AC:H)
Even with access, the exploit needs extra luck, timing, or a fussy environment to actually work.
Privileges required (PR:L)
A normal user session is enough; they don’t have to be admin.
User interaction (UI:N)
Nobody has to click “OK” or open a trap file; it can work without a victim helping.
Scope (S:U)
Damage stays in the same “trust bubble” as the broken component—no big spill into unrelated systems.
Confidentiality (C:H)
Serious risk that confidential data gets exposed in a big way.
Integrity (I:H)
They could widely tamper with or forge data—trust in the data is badly hurt.
Availability (A:H)
Could take the service down hard or make it unusable for people who depend on it.
 1.0 5.9 [email protected]
4.4 2.0 MEDIUM
AV:L/AC:M/Au:N/C:P/I:P/A:P Click to expand
Access vector (AV:L)
Requires local access to the target system.
Access complexity (AC:M)
Exploitation needs some favorable conditions, but not exceptional ones.
Authentication (AU:N)
No authentication is required.
Confidentiality impact (C:P)
Partial confidentiality impact.
Integrity impact (I:P)
Partial integrity impact.
Availability impact (A:P)
Partial availability impact.
 3.4 6.4 [email protected]

Weakness enumeration for CVE-2018-12029

GitHub Security Advisory for CVE-2018-12029

GHSA-jjcj-fgfm-9g9r · Severity: high · Ecosystem: rubygems — Phusion Passenger Race Condition Allows Privilege Escalation

OS Trackers for CVE-2018-12029

vendor priority summary link
debian unimportant CVE-2018-12029 unimportant priority: Debian including 1 source packages (passenger), 5 status rows across 5 suites (bookworm, bullseye, forky, sid, trixie): resolved 5. https://security-tracker.debian.org/tracker/CVE-2018-12029
gentoo normal CVE-2018-12029: 1 GLSA(s) (201807-02), 1 atom(s) (www-apache/passenger); latest impact normal. https://bugs.gentoo.org/buglist.cgi?quicksearch=CVE-2018-12029
redhat high — https://access.redhat.com/security/cve/CVE-2018-12029
suse medium CVE-2018-12029 severity moderate: SUSE including 8 source package names (ruby2.1-rubygem-passenger-5.0.18-12.9.1, ruby2.7-rubygem-passenger-6.0.8-3.2, …), 8 product×package rows across 2 product lines (SUSE Linux Enterprise Module for Containers 12, openSUSE Tumbleweed): Fixed 8. https://www.suse.com/security/cve/CVE-2018-12029/
ubuntu medium CVE-2018-12029 medium priority: Ubuntu including 2 source packages (passenger, ruby-passenger), 26 status rows across 13 suites (artful, bionic, cosmic, disco, eoan, focal, groovy, hirsute, impish, jammy, trusty, upstream, xenial): DNE 13, not-affected 6, released 5, ignored 1, needs-triage 1. https://ubuntu.com/security/CVE-2018-12029

Affected software / configurations for CVE-2018-12029

Vendor Product Version Raw CPE
phusion passenger >= 3.0.0, < 5.3.2 cpe:2.3:a:phusion:passenger:*:*:*:*:*:*:*:*
debian debian_linux 8.0 cpe:2.3:o:debian:debian_linux:8.0:*:*:*:*:*:*:*

References for CVE-2018-12029

cvelogic Threat Intelligence