CVE-2018-16476
HIGHCVE-2018-16476 is a high-severity (CVSS 7.5) CWE-284 vulnerability in activejob. 1 public exploit reference exists, so weaponization risk is real. O3 Security confirms whether CVE-2018-16476 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Improper Access Control in activejob
Blast Radius
activejob💎activejob💎activejob💎activejobReal-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
A Broken Access Control vulnerability in Active Job versions >= 4.2.0 allows an attacker to craft user input which can cause Active Job to deserialize it using GlobalId and give them access to information that they should not have. This vulnerability has been fixed in versions 4.2.11, 5.0.7.1, 5.1.6.1, and 5.2.1.1.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 💎RubyGems | activejob | ≥ 4.2.0&&< 4.2.11 | 4.2.11 |
| 💎RubyGems | activejob | ≥ 5.0.0&&< 5.0.7.1 | 5.0.7.1 |
| 💎RubyGems | activejob | ≥ 5.1.0&&< 5.1.6.1 | 5.1.6.1 |
| 💎RubyGems | activejob | ≥ 5.2.0&&< 5.2.1.1 | 5.2.1.1 |
Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for activejob. 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 activejob to 4.2.11 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2018-16476 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-2018-16476 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-2018-16476. 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-2018-16476 in your dependencies?
O3 detects CVE-2018-16476 across RubyGems dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.