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CVE-2019-5420 — Use of Insufficiently Random Values in railties —...

CRITICAL

Use of Insufficiently Random Values in Railties Allows Remote Code Execution

Published March 13, 2019Updated February 22, 2024Source: osv

Summary

# Possible Remote Code Execution Exploit in Rails Development Mode Impact ------ With some knowledge of a target application it is possible for 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. All users running an affected release should either upgrade or use one of the workarounds immediately. Releases -------- The 6.0.0.beta3 and 5.2.2.1 releases are available at the normal locations. Workarounds ----------- This issue can be mitigated by specifying a secret key in development mode. In "config/environments/development.rb" add this: ``` config.secret_key_base = SecureRandom.hex(64) ``` Please note that only the 5.2.x, 5.1.x, 5.0.x, and 4.2.x series are supported at present. Users of earlier unsupported releases are advised to upgrade as soon as possible as we cannot guarantee the continued availability of security fixes for unsupported releases. Credits ------- Thanks to ooooooo_q

Advisory Timeline

  • First published March 13, 2019 (2770 days ago).
  • Last revised February 22, 2024 — 1807 days after initial publication.

Remediation

Upgrade to the fixed version using your package manager.

Bundler
Update railties to 5.2.2.1 or later
gem install railties -v 5.2.2.1

After upgrading, run your dependency scanner again to confirm the vulnerability is resolved.

Affected Packages (1)

Affects 1 ecosystem: rubygems (1).

PackageEcosystemAffectedFixed In
railties
rubygems
5.2.0, 5.2.1, 5.2.1.1, 5.2.1.rc1 (+2 more)5.2.2.1

Vulnerability Classification

Common Weakness Enumeration (CWE) identifiers for this vulnerability type.

CVSS Score Breakdown

What the CVSS (Common Vulnerability Scoring System) 9.8 score means for each attack dimension.

Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
None
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High

CVSS:3.0/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:H

References

Frequently Asked Questions

What is CVE-2019-5420?
Use of Insufficiently Random Values in Railties Allows Remote Code Execution This vulnerability has been assigned a severity rating of CRITICAL (CVSS score: 9.8/10).
How do I check if my project is affected by CVE-2019-5420?
CVE-2019-5420 affects railties. Use GeekWala's free vulnerability scanner to check your dependencies against CVE-2019-5420 and 200,000+ other known vulnerabilities.

Severity & Exploitability

CVSS Score
9.8

Exploitation is straightforward and causes maximum impact. Patch immediately.

Also Known As

GHSA-m42h-mh85-4qgc

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