GHSA-8727-m6gj-mc37
Possible Strong Parameters Bypass in ActionPack
Packages
| Ecosystem | Package | Affected | Fixed in |
|---|---|---|---|
| RubyGems | actionpack | >= 5.0.0, < 5.2.4.3 | 5.2.4.3 |
| RubyGems | actionpack | >= 6.0.0, < 6.0.3.1 | 6.0.3.1 |
Details
As written in the advisory (Markdown source, shown as plain text).
There is a strong parameters bypass vector in ActionPack.
Versions Affected: rails <= 6.0.3
Not affected: rails < 5.0.0
Fixed Versions: rails >= 5.2.4.3, rails >= 6.0.3.1
Impact
------
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.
Impacted code will look something like this:
```
def update
# Attacker has included the parameter: `{ is_admin: true }`
User.update(clean_up_params)
end
def clean_up_params
params.each { |k, v| SomeModel.check(v) if k == :name }
end
```
Note the mistaken use of `each` in the `clean_up_params` method in the above
example.
Workarounds
-----------
Do not use the return values of `each`, `each_value`, or `each_pair` in your
application.
References
External links from the advisory. They lead to third-party sites.
- https://nvd.nist.gov/vuln/detail/CVE-2020-8164
- https://hackerone.com/reports/292797
- https://github.com/rails/rails
- https://github.com/rubysec/ruby-advisory-db/blob/master/gems/actionpack/CVE-2020-8164.yml
- https://groups.google.com/forum/#!topic/rubyonrails-security/f6ioe4sdpbY
- https://groups.google.com/g/rubyonrails-security/c/f6ioe4sdpbY
- https://lists.debian.org/debian-lts-announce/2020/06/msg00022.html
- https://lists.debian.org/debian-lts-announce/2020/07/msg00013.html
- https://www.debian.org/security/2020/dsa-4766
- http://lists.opensuse.org/opensuse-security-announce/2020-09/msg00089.html
- http://lists.opensuse.org/opensuse-security-announce/2020-09/msg00093.html
- http://lists.opensuse.org/opensuse-security-announce/2020-09/msg00107.html