GHSA-vfmv-jfc5-pjjw
MEDIUMCarrierWave content-Type allowlist bypass vulnerability which possibly leads to XSS remained
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
Blast Radius
carrierwave💎carrierwaveReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects RubyGems packages — download data is not available via public APIs for these ecosystems.
Description
Impact
The vulnerability CVE-2023-49090 wasn't fully addressed.
This vulnerability is caused by the fact that when uploading to object storage, including Amazon S3, it is possible to set a Content-Type value that is interpreted by browsers to be different from what's allowed by content_type_allowlist, by providing multiple values separated by commas.
This bypassed value can be used to cause XSS.
Patches
Workarounds
Use the following monkey patch to let CarrierWave parse the Content-type by using Marcel::MimeType.for.
# For CarrierWave 3.x
CarrierWave::SanitizedFile.class_eval do
def declared_content_type
@declared_content_type ||
if @file.respond_to?(:content_type) && @file.content_type
Marcel::MimeType.for(declared_type: @file.content_type.to_s.chomp)
end
end
end
# For CarrierWave 2.x
CarrierWave::SanitizedFile.class_eval do
def existing_content_type
if @file.respond_to?(:content_type) && @file.content_type
Marcel::MimeType.for(declared_type: @file.content_type.to_s.chomp)
end
end
end
References
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 💎RubyGems | carrierwave | ≥ 3.0.0&&< 3.0.7 | 3.0.7 |
| 💎RubyGems | carrierwave | all versions | 2.2.6 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for carrierwave. O3's reachability analysis confirms whether the vulnerable code path is actually invoked in your application, so you act on real exposure instead of every transitive match.
Fix
Update carrierwave to 3.0.7 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-vfmv-jfc5-pjjw is resolved across your whole dependency graph.
Workarounds
If you can't upgrade right away: gate or disable the affected feature, validate untrusted input at the boundary, and avoid passing attacker-controlled data into the vulnerable path. O3's runtime protection blocks exploitation in production as an interim safeguard until the upgrade lands.
How O3 protects you
O3 pinpoints whether GHSA-vfmv-jfc5-pjjw is reachable in your code and exactly where to fix it, then blocks exploitation in production at runtime until the patched version is deployed.
Tailored to GHSA-vfmv-jfc5-pjjw. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-vfmv-jfc5-pjjw in your dependencies?
O3 detects GHSA-vfmv-jfc5-pjjw across RubyGems dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.