CVE-2024-21510
MEDIUMCVE-2024-21510 is a medium-severity (CVSS 5.4) CWE-807 vulnerability in sinatra. O3 Security confirms whether CVE-2024-21510 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Sinatra vulnerable to Reliance on Untrusted Inputs in a Security Decision
Blast Radius
sinatraReal-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
Versions of the package sinatra from 0.0.0 are vulnerable to Reliance on Untrusted Inputs in a Security Decision via the X-Forwarded-Host (XFH) header. When making a request to a method with redirect applied, it is possible to trigger an Open Redirect Attack by inserting an arbitrary address into this header. If used for caching purposes, such as with servers like Nginx, or as a reverse proxy, without handling the X-Forwarded-Host header, attackers can potentially exploit Cache Poisoning or Routing-based SSRF.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 💎RubyGems | sinatra | all versions | 4.1.0 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for sinatra. 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 sinatra to 4.1.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2024-21510 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 CVE-2024-21510 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 CVE-2024-21510. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2024-21510 in your dependencies?
O3 detects CVE-2024-21510 across RubyGems dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.