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CVE-2019-5420
CRITICAL
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.
Published: Mar 27, 2019
Modified: Jun 17, 2026
CWE-77
CWE-330
CVSS Metrics
CVSSv3
Attack Vector:
NETWORK
Attack Complexity:
LOW
Privileges Required:
NONE
User Interaction:
NONE
Scope:
UNCHANGED
Confidentiality Impact:
HIGH
Integrity Impact:
HIGH
Availability Impact:
HIGH
CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H
Affected Products (5)
| Vendor | Product | Version |
|---|---|---|
| rubyonrails | rails | * < 5.2.2.1 |
| rubyonrails | rails | 6.0.0 |
| rubyonrails | rails | 6.0.0 |
| debian | debian_linux | 8.0 |
| fedoraproject | fedora | 30 |
GitHub Security Advisory GHSA-m42h-mh85-4qgc
Use of Insufficiently Random Values in Railties Allows Remote Code Execution
rubygems
railties
>= 5.2.0, <= 5.2.2.0
Fixed: 5.2.2.1
References (10)
- http://packetstormsecurity.com/files/152704/Ruby-On-Rails-DoubleTap-Development-Mode-secret_key_base-Remote-Code-Execution.html Exploit, Third Party Advisory, VDB Entry
- https://groups.google.com/forum/#%21topic/rubyonrails-security/IsQKvDqZdKw
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/Y43636TH4D6T46IC6N2RQVJTRFJAAYGA/
- https://weblog.rubyonrails.org/2019/3/13/Rails-4-2-5-1-5-1-6-2-have-been-released/ Patch, Vendor Advisory
- https://www.exploit-db.com/exploits/46785/ Exploit, Third Party Advisory, VDB Entry
- http://packetstormsecurity.com/files/152704/Ruby-On-Rails-DoubleTap-Development-Mode-secret_key_base-Remote-Code-Execution.html Exploit, Third Party Advisory, VDB Entry
- https://groups.google.com/forum/#%21topic/rubyonrails-security/IsQKvDqZdKw
- https://lists.fedoraproject.org/archives/list/package-announce%40lists.fedoraproject.org/message/Y43636TH4D6T46IC6N2RQVJTRFJAAYGA/
- https://weblog.rubyonrails.org/2019/3/13/Rails-4-2-5-1-5-1-6-2-have-been-released/ Patch, Vendor Advisory
- https://www.exploit-db.com/exploits/46785/ Exploit, Third Party Advisory, VDB Entry
Risk Scores
CVSS Score
9.8 / 10
EPSS Score
92.14%
Top 0% most likely to be exploited
Threat Score
76.8 / 100
Data Sources
NVD
EPSS
GitHub