Rails
CVE-2019-5420
CRITICAL
Vulnerability Assessment
| Weakness |
CWE
OWASP Top 10:2025
A05:2025 - Injection
ASVS 5.0
V1 - Encoding and Sanitization Command injection prevention
MITRE ATT&CK
1 technique across 1 tactic: Execution The technique list with ATT&CK links and the kill-chain view is part of the Basic plan and up. |
| Impact | CVSS score of 9.8 (CRITICAL). Attack characteristics: network attack vector, low complexity, no privileges required, no user interaction not required. Public proof-of-concept exploit code is available. |
| Exploit ScenarioDerived | A remote attacker could inject arbitrary commands into system command execution by sending crafted requests to the affected application. No authentication is required to exploit this vulnerability. |
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Alert meAnalysisAI
A remote code execution vulnerability in development mode Rails <5.2.2.1, <6.0.0.beta3 can allow an attacker to guess the automatically generated development mode secret token. Rated critical severity (CVSS 9.8), this vulnerability is remotely exploitable, no authentication required, low attack complexity. Public exploit code available.
RemediationAI
A vendor patch is available. Apply the latest security update as soon as possible. Use parameterized APIs, avoid shell execution, validate input with strict allowlists.
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 as Command Injection (CWE-77), which allows attackers to inject arbitrary commands into system command execution. A remote code execution vulnerability in development mode Rails <5.2.2.1, <6.0.0.beta3 can allow an attacker to guess the automatically generated development mode secret token. This secret token can be used in combination with other Rails internals to escalate to a remote code execution exploit. Affected products include: Rubyonrails Rails, Debian Debian Linux, Fedoraproject Fedora.
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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
A remote code execution vulnerability in development mode Rails <5.2.2.1, <6.0.0.beta3 can allow an attacker to guess the automatically generated development mode secret token. This secret token can be used in combination with other Rails internals to escalate to a remote code execution exploit.
Threat Intelligence Overview
NVD
CVE.org
EPSS
Exploit-DB
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
OS command injection occurs when an application passes unsanitized user input directly into system shell commands.
Remote Code Execution represents the critical moment when an attacker successfully runs arbitrary code on a target system without physical access.
Affected Products (CPE)NVD
Directory traversal vulnerability in Action View in Ruby on Rails before 3.2.22.1, 4.0.x and 4.1.x before 4.1.14.1, 4.2.
lib/active_support/json/backends/yaml.rb in Ruby on Rails 2.3.x before 2.3.16 and 3.0.x before 3.0.20 does not properly
active_support/core_ext/hash/conversions.rb in Ruby on Rails before 2.3.15, 3.0.x before 3.0.19, 3.1.x before 3.1.10, an
Action Pack in Ruby on Rails before 3.2.22.2, 4.x before 4.1.14.2, and 4.2.x before 4.2.5.2 allows remote attackers to e
Directory traversal vulnerability in actionpack/lib/abstract_controller/base.rb in the implicit-render implementation in
actionpack/lib/action_view/lookup_context.rb in Action View in Ruby on Rails 3.x before 3.2.16 and 4.x before 4.0.2 allo
A deserialization of untrusted data vulnernerability exists in rails < 5.2.4.3, rails < 6.0.3.1 that can allow an attack
The is a code injection vulnerability in versions of Rails prior to 5.0.1 that wouldallow an attacker who controlled the
SQL injection vulnerability in the 'where' method in Ruby on Rails 5.1.4 and earlier allows remote attackers to execute
SQL injection vulnerability in the 'find_by' method in Ruby on Rails 5.1.4 and earlier allows remote attackers to execut
SQL injection vulnerability in the Active Record component in Ruby on Rails before 3.0.18, 3.1.x before 3.1.9, and 3.2.x
The Active Record component in Ruby on Rails before 3.0.14, 3.1.x before 3.1.6, and 3.2.x before 3.2.6 does not properly
GitHub PoC