CVE-2019-5419 — actionview
HIGHCVE-2019-5419 is a high-severity (CVSS 7.5) Uncontrolled Resource Consumption vulnerability in actionview. 2 public exploit references exist, so weaponization risk is real. A fix is available for actionview — see the affected versions and patch details below.
Denial of Service Vulnerability in Action View
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.
How urgent is this, really
CVE-2019-5419 plotted by exploitation likelihood (EPSS) against impact (CVSS). The shaded corner — EPSS 50%+ and CVSS 7.0+ — is where this CVE doesn't sit, though severity or exploitability alone can still warrant action.
Where this sits among everything scored
Of 377,166 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Real counts from FIRST.org, not a sample — log-scaled since the landscape is heavily right-skewed.
Real-World Exposure
actionview💎actionview💎actionview💎actionview💎actionviewReal-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
There is a possible denial of service vulnerability in Action View (Rails) <5.2.2.1, <5.1.6.2, <5.0.7.2, <4.2.11.1 where specially crafted accept headers can cause action view to consume 100% cpu and make the server unresponsive.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 💎RubyGems | actionview | ≥ 4.0.0&&< 4.2.11.1 | 4.2.11.1bundle update actionview --conservative |
| 💎RubyGems | actionview | ≥ 5.2.0&&< 5.2.2.1 | 5.2.2.1bundle update actionview --conservative |
| 💎RubyGems | actionview | ≥ 5.1.0&&< 5.1.6.2 | 5.1.6.2bundle update actionview --conservative |
| 💎RubyGems | actionview | ≥ 5.0.0&&< 5.0.7.2 | 5.0.7.2bundle update actionview --conservative |
| 💎RubyGems | actionview | ≥ 6.0.0.beta1&&< 6.0.0.beta3 | 6.0.0.beta3bundle update actionview --conservative |
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 actionview, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update actionview to 4.2.11.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2019-5419 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 Security's impact-aware SCA analyses which vulnerable code paths your application actually calls, so a match like CVE-2019-5419 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2019-5419. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Fixing This On Your OS
If you run this on a Linux distribution, patch through your package manager against the distro's own security advisory below — it tracks the exact backported fix for your release, which can ship on a different timeline (and sometimes a different severity) than the upstream project.
This issue did affect the versions of rh-ror42-rubygem-actionview and rh-ror50-rubygem-actionview as shipped with Red Hat Software Collections.
| Product | Fixed in | Advisory |
|---|---|---|
| CloudForms Management Engine 5.10 | ansible-tower-0:3.4.3-1.el7at | RHSA-2019:0796 |
| CloudForms Management Engine 5.9 | cfme-0:5.9.9.3-1.el7cf | RHSA-2019:1289 |
| Red Hat Software Collections for Red Hat Enterprise Linux 6 | rh-ror50-rubygem-actionpack-1:5.0.1-2.el6 | RHSA-2019:1147 |
| Red Hat Software Collections for Red Hat Enterprise Linux 6 | rh-ror42-rubygem-actionpack-1:4.2.6-5.el6 | RHSA-2019:1149 |
Frequently Asked Questions
Is CVE-2019-5419 in your dependencies?
O3 Security finds CVE-2019-5419 across RubyGems dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.