CVE-2017-9303
MEDIUMCVE-2017-9303 is a medium-severity (CVSS 6.1) Improper Input Validation vulnerability in laravel/laravel. O3 Security confirms whether CVE-2017-9303 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Laravel does not properly constrain the host portion of a password-reset URL
Blast Radius
laravel/laravel🐘illuminate/auth🐘illuminate/auth🐘laravel/framework🐘laravel/frameworkReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Packagist packages — download data is not available via public APIs for these ecosystems.
Description
Laravel 5.4.x before 5.4.22 does not properly constrain the host portion of a password-reset URL, which makes it easier for remote attackers to conduct phishing attacks by specifying an attacker-controlled host.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | laravel/laravel | ≥ 5.4.0&&< 5.4.22 | 5.4.22 |
| 🐘Packagist | illuminate/auth | ≥ 5.3.0 | No fix |
| 🐘Packagist | illuminate/auth | ≥ 5.4.0&&< 5.4.22 | 5.4.22 |
| 🐘Packagist | laravel/framework | ≥ 5.3.0 | No fix |
| 🐘Packagist | laravel/framework | ≥ 5.4.0&&< 5.4.22 | 5.4.22 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for laravel/laravel. 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 laravel/laravel to 5.4.22 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2017-9303 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-2017-9303 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-2017-9303. 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-2017-9303 in your dependencies?
O3 detects CVE-2017-9303 across Packagist dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.