Two vulnerabilities were found in Ruby on Rails, a MVC ruby-based framework geared for web application development, which could lead to remote code execution and untrusted user input usage, depending on the application.

• CVE-2020-8164

  Strong parameters bypass vector in ActionPack. In some cases user supplied information can be inadvertently leaked from Strong Parameters. Specifically the return value of `each`, or `each_value`, or `each_pair` will return the underlying untrusted hash of data that was read from the parameters. Applications that use this return value may be inadvertently use untrusted user input.

• CVE-2020-8165

  Potentially unintended unmarshalling of user-provided objects in MemCacheStore. There is potentially unexpected behaviour in the MemCacheStore where, when untrusted user input is written to the cache store using the `raw: true` parameter, re-reading the result from the cache can evaluate the user input as a Marshalled object instead of plain text. Unmarshalling of untrusted user input can have impact up to and including RCE. At a minimum, this vulnerability allows an attacker to inject untrusted Ruby objects into a web application.

  In addition to upgrading to the latest versions of Rails, developers should ensure that whenever they are calling `Rails.cache.fetch` they are using consistent values of the `raw` parameter for both reading and writing.

For Debian 8 Jessie, these problems have been fixed in version 2:4.1.8-1+deb8u7.

We recommend that you upgrade your rails packages.

Further information about Debian LTS security advisories, how to apply these updates to your system and frequently asked questions can be found at: https://wiki.debian.org/LTS