Passenger
CVE-2018-12026
CRITICAL
Vulnerability Assessment
| Weakness |
CWE
OWASP Top 10:2025
A01:2025 - Broken Access Control
ASVS 5.0
V5 - File Handling Symlink resolution safety
|
| Impact | CVSS score of 9.8 (CRITICAL). Attack characteristics: network attack vector, low complexity, no privileges required, no user interaction not required. |
| Exploit ScenarioDerived | This vulnerability can be exploited remotely over the network. Successful exploitation could compromise the critical-severity affected system. |
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Alert meAnalysisAI
During the spawning of a malicious Passenger-managed application, SpawningKit in Phusion Passenger 5.3.x before 5.3.2 allows such applications to replace key files or directories in the spawning. Rated critical severity (CVSS 9.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. No vendor patch available.
RemediationAI
No vendor patch is available at time of analysis. Monitor vendor advisories for updates. Apply vendor patches when available. Implement network segmentation and monitoring as interim mitigations.
Affected Packages
Source: OSV (Open Source Vulnerabilities)
Affects your stack
Affects 1 package in rubygems
Checking this CVE against your own stacks and servers is part of the Basic plan and up.
Technical ContextAI · show details
This vulnerability is classified under CWE-59. During the spawning of a malicious Passenger-managed application, SpawningKit in Phusion Passenger 5.3.x before 5.3.2 allows such applications to replace key files or directories in the spawning communication directory with symlinks. This then could result in arbitrary reads and writes, which in turn can result in information disclosure and privilege escalation. Affected products include: Phusion Passenger. Version information: before 5.3.2.
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- Exploit and PoC references, threat intelligence from 22 sources
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Severity by source
AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Primary rating from NVD · only source for this CVE.
CVSS VectorNVD
DescriptionNVD
During the spawning of a malicious Passenger-managed application, SpawningKit in Phusion Passenger 5.3.x before 5.3.2 allows such applications to replace key files or directories in the spawning communication directory with symlinks. This then could result in arbitrary reads and writes, which in turn can result in information disclosure and privilege escalation.
Threat Intelligence Overview
NVD
CVE.org
EPSS
How this decision was reached
The engine reads each signal below and applies a fixed list of rules from top to bottom. The first rule that matches sets the recommended action – like a statement, every line is shown.
What every action level means
SSVC AssessmentENISA
Priority Score
Attack Technique
Privilege escalation occurs when an attacker leverages flaws in access control mechanisms to gain permissions beyond what they were originally granted.
Information disclosure occurs when an application unintentionally exposes sensitive data that aids attackers in reconnaissance or directly compromises security.
Affected Products (CPE)NVD
An Insecure Permissions vulnerability in SpawningKit in Phusion Passenger 5.3.x before 5.3.2 causes information disclosu
In Phusion Passenger before 5.1.0, a known /tmp filename was used during passenger-install-nginx-module execution, which
An Incorrect Access Control vulnerability in SpawningKit in Phusion Passenger 5.3.x before 5.3.2 allows a Passenger-mana
A race condition in the nginx module in Phusion Passenger 3.x through 5.x before 5.3.2 allows local escalation of privil
The http parser in Phusion Passenger 6.0.21 through 6.0.25 before 6.0.26 allows a denial of service during parsing of a
An issue was discovered in switchGroup() in agent/ExecHelper/ExecHelperMain.cpp in Phusion Passenger before 5.3.2. Rated
In agent/Core/SpawningKit/Spawner.h in Phusion Passenger 5.1.10 (fixed in Passenger Open Source 5.1.11 and Passenger Ent
Phusion Passenger gem before 3.0.21 and 4.0.x before 4.0.5 for Ruby allows local users to cause a denial of service (pre
ext/common/ServerInstanceDir.h in Phusion Passenger gem before 4.0.6 for Ruby allows local users to gain privileges or p
Phusion Passenger 4.0.37 allows local users to write to certain files and directories via a symlink attack on (1) contro
Phusion Passenger before 4.0.37 allows local users to write to certain files and directories via a symlink attack on (1)
GitHub PoC
Exploit-DB