[WIP] Fix actionpack remote code execution vulnerability

[Copilot]

Thanks for assigning this alert to me. I'm starting to work on it and will keep this PR's description up to date as I form a plan and make progress.

Original prompt

---

This section details the Dependabot vulnerability alert you should resolve

<alert_title>actionpack allows remote code execution via application's unrestricted use of render method</alert_title>
<alert_description>Action Pack in Ruby on Rails before 3.2.22.2, 4.x before 4.1.14.2, and 4.2.x before 4.2.5.2 allows remote attackers to execute arbitrary Ruby code by leveraging an application's unrestricted use of the render method.</alert_description>

high
GHSA-78rc-8c29-p45g, CVE-2016-2098
actionpack
RubyGems
<vulnerable_versions>= 4.0.0</vulnerable_versions>
<patched_version>4.1.14.2</patched_version>
<manifest_path>Gemfile.lock</manifest_path>

https://nvd.nist.gov/vuln/detail/CVE-2016-2098 https://www.exploit-db.com/exploits/40086/ http://lists.opensuse.org/opensuse-security-announce/2016-03/msg00057.html http://lists.opensuse.org/opensuse-security-announce/2016-03/msg00080.html http://lists.opensuse.org/opensuse-security-announce/2016-03/msg00083.html http://lists.opensuse.org/opensuse-security-announce/2016-03/msg00086.html http://lists.opensuse.org/opensuse-security-announce/2016-04/msg00006.html http://lists.opensuse.org/opensuse-security-announce/2016-04/msg00053.html http://weblog.rubyonrails.org/2016/2/29/Rails-4-2-5-2-4-1-14-2-3-2-22-2-have-been-released/ http://www.debian.org/security/2016/dsa-3509 https://web.archive.org/web/20200228015318/http://www.securityfocus.com/bid/83725 https://web.archive.org/web/20210612214217/https://groups.google.com/forum/message/raw?msg=rubyonrails-security/ly-IH-fxr_Q/WLoOhcMZIAAJ https://web.archive.org/web/20211205173437/https://securitytracker.com/id/1035122 https://github.com/rubysec/ruby-advisory-db/blob/master/gems/actionpack/CVE-2016-2098.yml https://groups.google.com/forum/#!topic/rubyonrails-security/ly-IH-fxr_Q https://copilot-work-finished-pr-indicator.review-lab.github.com/advisories/GHSA-78rc-8c29-p45g

<task_instructions>Resolve this alert by updating the affected package to a non-vulnerable version. Prefer the lowest non-vulnerable version (see the patched_version field above) over the latest to minimize breaking changes. Include a Reachability Assessment section in the PR description. Review the alert_description field to understand which APIs, features, or configurations are affected, then search the codebase for usage of those specific items. If the vulnerable code path is reachable, explain how (which files, APIs, or call sites use the affected functionality) and note that the codebase is actively exposed to this vulnerability. If the vulnerable code path is not reachable, explain why (e.g. the affected API is never called, the vulnerable configuration is not used) and note that the update is primarily to satisfy vulnerability scanners rather than to address an active risk. If the advisory is too vague to determine reachability (e.g. 'improper input validation' with no specific API named), state that reachability could not be determined and explain why. Include a confidence level in the reachability assessment (e.g. high confidence if the advisory names a specific API and you confirmed it is or is not called, low confidence if the usage is indirect and hard to trace). If no patched version is available, check the alert_description field for a Workarounds section — the advisory may describe configuration changes or usage patterns that mitigate the vulnerability without a version update. If a workaround is available, apply it and leave a code comment referencing the advisory identifier explaining it is a temporary mitigation. If neither a patch nor a workaround is available, explain in the PR description why the alert cannot be resolved automatically so a human reviewer can take over. Inspect the repository to determine which package manager is used (e.g. lock files, config files, build scripts) and use that tooling to perform the update — do not edit lock files directly. If the version constraint in the manifest (e.g. package.json, Gemfile, pyproject.toml) caps the version below the fix, update the constraint first. For transitive dependencies, determine whether it is simpler to update the direct dependency that pulls in the vulnerable package or to update the transitive dependency directly, and choose the least disruptive approach. If upgrading to fix the vulnerability forces a major version bump or known breaking changes, review the changelog or release notes, then audit the codebase for usage of affected APIs and fix any breaking changes that are found. If the package manager fails to resolve dependencies (e.g. peer dependency conflicts, incompatible engine constraints), document the error in the PR description rather than attempting increasingly...

• Resolves dsp-testing/dependabot-all-updates-test alert Bump fast-classpath-scanner from 2.18.1 to 3.1.15 #33