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.
Blast Radius
symfony/security-core🐘symfony/security-core🐘symfony/security-core🐘symfony/security-core🐘symfony/security🐘symfony/security🐘symfony/security🐘symfony/security+4 moreReal-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 the LDAP component in Symfony 2.8.x before 2.8.37, 3.3.x before 3.3.17, 3.4.x before 3.4.7, and 4.0.x before 4.0.7. It allows remote attackers to bypass authentication by logging in with a "null" password and valid username, which triggers an unauthenticated bind. NOTE: this issue exists because of an incomplete fix for CVE-2016-2403.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | symfony/security-core | ≥ 2.8.0&&< 2.8.37 | 2.8.37 |
| 🐘Packagist | symfony/security-core | ≥ 3.0.0&&< 3.3.17 | 3.3.17 |
| 🐘Packagist | symfony/security-core | ≥ 3.4.0&&< 3.4.7 | 3.4.7 |
| 🐘Packagist | symfony/security-core | ≥ 4.0.0&&< 4.0.7 | 4.0.7 |
| 🐘Packagist | symfony/security | ≥ 2.8.0&&< 2.8.37 | 2.8.37 |
| 🐘Packagist | symfony/security | ≥ 3.0.0&&< 3.3.17 | 3.3.17 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for symfony/security-core. 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 symfony/security-core to 2.8.37 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-35c5-28pg-2qg4 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 GHSA-35c5-28pg-2qg4 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 GHSA-35c5-28pg-2qg4. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is GHSA-35c5-28pg-2qg4 in your dependencies?
O3 detects GHSA-35c5-28pg-2qg4 across Packagist dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.