CVE-2025-55740
MEDIUMCVE-2025-55740 is a medium-severity (CVSS 6.5) CWE-1392 vulnerability in github.com/Anipaleja/nginx-defender. O3 Security confirms whether CVE-2025-55740 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Default Credentials in nginx-defender Configuration Files
Real-World Exposure
github.com/Anipaleja/nginx-defenderReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects Go packages — download data is not available via public APIs for these ecosystems.
Description
nginx-defender is a high-performance, enterprise-grade Web Application Firewall (WAF) and threat detection system engineered for modern web infrastructure. This is a configuration vulnerability affecting nginx-defender deployments. Example configuration files config.yaml and docker-compose.yml contain default credentials (default_password: "change_me_please", GF_SECURITY_ADMIN_PASSWORD=admin123). If users deploy nginx-defender without changing these defaults, attackers with network access could gain administrative control, bypassing security protections. The issue is addressed in v1.5.0 and later.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐹Go | github.com/Anipaleja/nginx-defender | all versions | 1.5.0 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for github.com/Anipaleja/nginx-defender. 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 github.com/Anipaleja/nginx-defender to 1.5.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2025-55740 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-2025-55740 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-2025-55740. 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-2025-55740 in your dependencies?
O3 detects CVE-2025-55740 across Go dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.