GHSA-m42h-mh85-4qgc

Use of Insufficiently Random Values in Railties Allows Remote Code Execution

Source: GitHub Advisory Database (reviewed) Critical CVE-2019-5420

Packages

Ecosystem	Package	Affected	Fixed in
RubyGems	railties	>= 5.2.0, < 5.2.2.1	5.2.2.1

Details

As written in the advisory (Markdown source, shown as plain text).

# 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

References

External links from the advisory. They lead to third-party sites.