[Security] Bump activestorage from 5.2.3 to 5.2.6

[dependabot-preview]

Bumps activestorage from 5.2.3 to 5.2.6. This update includes a security fix.

Vulnerabilities fixed

Sourced from The Ruby Advisory Database.

Circumvention of file size limits in ActiveStorage There is a vulnerability in ActiveStorage's S3 adapter that allows the Content-Length of a direct file upload to be modified by an end user.

Versions Affected: rails < 5.2.4.2, rails < 6.0.3.1 Not affected: Applications that do not use the direct upload functionality of the ActiveStorage S3 adapter. Fixed Versions: rails >= 5.2.4.3, rails >= 6.0.3.1

Impact

Utilizing this vulnerability, an attacker can control the Content-Length of an S3 direct upload URL without receiving a new signature from the server. This could be used to bypass controls in place on the server to limit upload size.

Workarounds

This is a low-severity security issue. As such, no workaround is necessarily until such time as the application can be upgraded.

Patched versions: ~> 5.2.4, >= 5.2.4.3; >= 6.0.3.1 Unaffected versions: none

Release notes

Sourced from activestorage's releases.

5.2.6

Active Support

• No changes.

Active Model

• No changes.

Active Record

• No changes.

Action View

• No changes.

Action Pack

• Accept base64_urlsafe CSRF tokens to make forward compatible.

  Base64 strict-encoded CSRF tokens are not inherently websafe, which makes them difficult to deal with. For example, the common practice of sending the CSRF token to a browser in a client-readable cookie does not work properly out of the box: the value has to be url-encoded and decoded to survive transport.

  In this version, we generate Base64 urlsafe-encoded CSRF tokens, which are inherently safe to transport. Validation accepts both urlsafe tokens, and strict-encoded tokens for backwards compatibility.

  How the tokes are encoded is controllr by the action_controller.urlsafe_csrf_tokens config.

  In Rails 5.2.5, the CSRF token format was accidentally changed to urlsafe-encoded.

  Atention: If you already upgraded your application to 5.2.5, set the config urlsafe_csrf_tokens to true, otherwise your form submission will start to fail during the deploy of this new version.

  Rails.application.config.action_controller.urlsafe_csrf_tokens = true

... (truncated)

Commits

• 4866154 Preparing for 5.2.6 release
• 4d68f67 Merge branch '5-2-sec' into 5-2-stable
• 2612683 Preparing for 5.2.4.6 release
• 9df84af Update changelog
• cb0a558 v5.2.5
• b5a7479 Upgrade to Marcel 1.0.0
• 6de08e5 Merge branch '5-2-sec' into 5-2-stable
• dc7364b Preparing for 5.2.4.5 release
• 2a3f8a2 Fix syntax error in S3 service test on Ruby < 2.5
• 5d0e5f0 Generate a preview without print margins
• Additional commits viewable in compare view

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