CVE-2019-5420A remote code execution vulnerability in development mode Rails <5.2.2.1, <6.0.0.beta3 can allow an attacker to guess the automatically…
- 9.8CriticalCVSS base score
- 89.3%Exploitation in 30 daysEPSS · top 0.2% of all CVEs
- NoKnown exploitednot in CISA's KEV catalog
- 2Public exploitsMetasploit, Nuclei and Exploit-DB
Description
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.
Public exploit
An exploit or proof of concept is public: anyone can try it against an unpatched system. The public collections list a Metasploit module and an Exploit-DB entry for it. A reference of the record is tagged as an exploit.
Show the exploits3
Metasploit modules1 module
- Ruby On Rails DoubleTap Development Mode secret_key_base Vulnerability (Metasploit module) (opens in a new tab)
exploit/multi/http/rails_double_tapRank excellentdisclosed 13 Mar 2019
Exploit-DB1 entry
- Ruby On Rails - DoubleTap Development Mode secret_key_base Remote Code Execution (Metasploit) (Exploit-DB entry) (opens in a new tab)
EDB-ID 46785remote, linuxpublished 2 May 2019Verified
References tagged exploit1 reference
- 46785 (opens in a new tab)exploitx_refsource_EXPLOIT-DBx_transferred
Modules, templates and exploits as listed by the Metasploit Framework (BSD-3-Clause), ProjectDiscovery's Nuclei templates (MIT) and the Exploit Database (GPLv2), read once a day. Where the data comes from
Timeline
ID reserved
By hackerone
- 3 months later
· 3 months later
Published
- 5 years later
· 5 years later
Record updated
Changes after publication (a new score, a public exploit, EPSS crossing 1, 10 or 50 %, leaving KEV) are kept since November 2026; earlier ones are not known.
Scores
| Scored by | CVSS | Score | Vector |
|---|---|---|---|
| NVDNVD · Modified | 3.1 | Critical9.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H |
- EPSS (exploitation in 30 days)
- 89.3% · top 0.2% of all CVEs (12 Nov 2026)
The list uses the assigner's score when there is one, then CISA's, then NVD's: Critical 9.8.
Affected products
Rails · https://github.com/rails/rails
- affected 5.2.2.1
- affected 6.0.0.beta3
Affected packages
From reviewed advisories of the GitHub Advisory Database.
- RubyGemsrailtiesGHSA-m42h-mh85-4qgc (opens in a new tab)
References
References5
- https://weblog.rubyonrails.org/2019/3/13/Rails-4-2-5-1-5-1-6-2-have-been-released/ (opens in a new tab)x_refsource_CONFIRMx_transferred
- https://groups.google.com/forum/#%21topic/rubyonrails-security/IsQKvDqZdKw (opens in a new tab)x_refsource_CONFIRMx_transferred
- http://packetstormsecurity.com/files/152704/Ruby-On-Rails-DoubleTap-Development-Mode-secret_key_base-Remote-Code-Execution.html (opens in a new tab)x_refsource_MISCx_transferred
- 46785 (opens in a new tab)exploitx_refsource_EXPLOIT-DBx_transferred
- FEDORA-2019-1cfe24db5c (opens in a new tab)vendor-advisoryx_refsource_FEDORAx_transferred
Sources
The same CVE in the primary databases and aggregators, to check against.
- CVE.org record (opens in a new tab)
- CVE List JSON (GitHub) (opens in a new tab)
- NVD (opens in a new tab)
- FIRST EPSS (opens in a new tab)
- EUVD EUVD-2019-0385 (opens in a new tab)
- OSV.dev (opens in a new tab)
- GitHub Advisory GHSA-m42h-mh85-4qgc (opens in a new tab)
- CIRCL Vulnerability-Lookup (opens in a new tab)
Badge for a README or a ticket
[](https://cveledger.app/cve/CVE-2019-5420)Record last updated .