GHSA-673x-f5wx-fxpw is a high-severity (CVSS 7.6) Cross-site Scripting (XSS) vulnerability in baserproject/basercms. O3 Security confirms whether GHSA-673x-f5wx-fxpw is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Cross Site Scripting and RCE in baserCMS
Real-World Exposure
baserproject/basercmsReal-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
baserCMS 4.3.6 and earlier is affected by Cross Site Scripting (XSS) and Remote Code Execution (RCE).
- Impact: XSS to RCE via Arbitrary file upload.
- Attack vector is: Administrator must be logged in.
- Components are: ThemeFilesController.php, UploaderFilesController.php.
- Tested baserCMS Version : 4.3.6 (Latest)
- Affected baserCMS Version : 4.2.0 ~ 4.3.6 (XSS), 3.0.10 ~ 4.3.6 (RCE)
- Patches : https://basercms.net/security/20200827
Found by Vulnerability Research team in Flatt Security Inc.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | baserproject/basercms | ≥ 4.0.0&&< 4.3.7 | 4.3.7 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for baserproject/basercms. 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 baserproject/basercms to 4.3.7 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-673x-f5wx-fxpw 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-673x-f5wx-fxpw 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-673x-f5wx-fxpw. 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-673x-f5wx-fxpw in your dependencies?
O3 detects GHSA-673x-f5wx-fxpw across Packagist dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.