CVE-2019-13647
MEDIUMCVE-2019-13647 is a medium-severity (CVSS 5.4) Cross-site Scripting (XSS) vulnerability in grumpydictator/firefly-iii. 1 public exploit reference exists, so weaponization risk is real. O3 Security confirms whether CVE-2019-13647 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Firefly III vulnerable to image-based stored XSS
Blast Radius
grumpydictator/firefly-iiiReal-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
Firefly III before 4.7.17.3 is vulnerable to stored XSS due to lack of filtration of user-supplied data in image file content. The JavaScript code is executed during attachments/view/$file_id$ attachment viewing. NOTE: It is asserted that an attacker must have the same access rights as the user in order to be able to execute the vulnerability
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | grumpydictator/firefly-iii | all versions | 4.7.17.3 |
Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for grumpydictator/firefly-iii. 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 grumpydictator/firefly-iii to 4.7.17.3 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2019-13647 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-2019-13647 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-2019-13647. 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-2019-13647 in your dependencies?
O3 detects CVE-2019-13647 across Packagist dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.