CVE-2017-16654 is a high-severity (CVSS 7.5) Path Traversal vulnerability in symfony/intl. A fix is available for symfony/intl — see the affected versions and patch details below.
Symfony Directory Traversal
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-2017-16654 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 377,333 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
symfony/intl🐘symfony/intl🐘symfony/intl🐘symfony/intl🐘symfony/symfony🐘symfony/symfony🐘symfony/symfony🐘symfony/symfonyReal-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
An issue was discovered in Symfony before 2.7.38, 2.8.31, 3.2.14, 3.3.13, 3.4-BETA5, and 4.0-BETA5. The Intl component includes various bundle readers that are used to read resource bundles from the local filesystem. The read() methods of these classes use a path and a locale to determine the language bundle to retrieve. The locale argument value is commonly retrieved from untrusted user input (like a URL parameter). An attacker can use this argument to navigate to arbitrary directories via the dot-dot-slash attack, aka Directory Traversal.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | symfony/intl | ≥ 2.7.0&&< 2.7.38 | 2.7.38composer require symfony/intl:^2.7.38 |
| 🐘Packagist | symfony/intl | ≥ 2.8.0&&< 2.8.31 | 2.8.31composer require symfony/intl:^2.8.31 |
| 🐘Packagist | symfony/intl | ≥ 3.0.0&&< 3.2.14 | 3.2.14composer require symfony/intl:^3.2.14 |
| 🐘Packagist | symfony/intl | ≥ 3.3.0&&< 3.3.13 | 3.3.13composer require symfony/intl:^3.3.13 |
| 🐘Packagist | symfony/symfony | ≥ 2.7.0&&< 2.7.38 | 2.7.38composer require symfony/symfony:^2.7.38 |
| 🐘Packagist | symfony/symfony | ≥ 2.8.0&&< 2.8.31 | 2.8.31composer require symfony/symfony:^2.8.31 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for symfony/intl, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update symfony/intl to 2.7.38 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2017-16654 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-2017-16654 can be triaged on real exposure rather than presence alone.
Tailored to CVE-2017-16654. 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-2017-16654 in your dependencies?
O3 Security finds CVE-2017-16654 across Packagist dependencies, including transitive ones, and its impact-aware SCA ranks findings by whether your code actually calls the vulnerable path.