GHSA-2p68-f74v-9wc6 ActiveSupport potentially unintended unmarshalling of user-provided objects in MemCacheStore and RedisCacheStore

• RubyGems activesupport: >= 5.0.0, < 5.2.4.3 → fixed in 5.2.4.3 • RubyGems activesupport: >= 6.0.0, < 6.0.3.1 → fixed in 6.0.3.1

In ActiveSupport, there is potentially unexpected behaviour in the MemCacheStore and RedisCacheStore 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. Vulnerable code looks like: ``` data = cache.fetch("demo", raw: true) { untrusted_string } ``` Versions Affected: rails = 5.2.4.3, rails >= 6.0.3.1 Impact ------ 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, especially in the case of the RedisCacheStore which does not, prior to these changes, detect if data was serialized using the raw option upon deserialization. Workarounds ----------- It is recommended that application developers apply the suggested patch or upgrade to the latest release as soon as possible. If this is not possible, we recommend ensuring that all user-provided strings cached using the `raw` argument should be double-checked to ensure that they conform to the expected format.