Headline
CVE-2023-49090: Content-Type allowlist bypass vulnerability, possibly leading to XSS
CarrierWave is a solution for file uploads for Rails, Sinatra and other Ruby web frameworks. CarrierWave has a Content-Type allowlist bypass vulnerability, possibly leading to XSS. The validation in allowlisted_content_type? determines Content-Type permissions by performing a partial match. If the content_type argument of allowlisted_content_type? is passed a value crafted by the attacker, Content-Types not included in the content_type_allowlist will be allowed. This issue has been patched in versions 2.2.5 and 3.0.5.
Impact
CarrierWave::Uploader::ContentTypeAllowlist has a Content-Type allowlist bypass vulnerability, possibly leading to XSS.
The validation in allowlisted_content_type? determines Content-Type permissions by performing a partial match.
If the content_type argument of allowlisted_content_type? is passed a value crafted by the attacker, Content-Types not included in the content_type_allowlist will be allowed.
In addition, by setting the Content-Type configured by the attacker at the time of file delivery, it is possible to cause XSS on the user’s browser when the uploaded file is opened.
Patches
Upgrade to 3.0.5 or 2.2.5.
Workarounds
When validating with allowlisted_content_type? in CarrierWave::Uploader::ContentTypeAllowlist , forward match(\A) the Content-Type set in content_type_allowlist, preventing unintentional permission of text/html;image/png when you want to allow only image/png in content_type_allowlist.
References
OWASP - File Upload Cheat Sheet
Related news
### Impact [CarrierWave::Uploader::ContentTypeAllowlist](https://github.com/carrierwaveuploader/carrierwave/blob/master/lib/carrierwave/uploader/content_type_allowlist.rb) has a Content-Type allowlist bypass vulnerability, possibly leading to XSS. The validation in `allowlisted_content_type?` determines Content-Type permissions by performing a partial match. If the `content_type` argument of `allowlisted_content_type?` is passed a value crafted by the attacker, Content-Types not included in the `content_type_allowlist` will be allowed. In addition, by setting the Content-Type configured by the attacker at the time of file delivery, it is possible to cause XSS on the user's browser when the uploaded file is opened. ### Patches Upgrade to [3.0.5](https://rubygems.org/gems/carrierwave/versions/3.0.5) or [2.2.5](https://rubygems.org/gems/carrierwave/versions/2.2.5). ### Workarounds When validating with `allowlisted_content_type?` in [CarrierWave::Uploader::ContentTypeAllowlist](https:...