C5 Firefly III CSV InjectionGHSA-29w6-c52g-m8jc
MEDIUMGHSA-29w6-c52g-m8jc is a medium-severity (CVSS 4) remote code execution vulnerability in grumpydictator/firefly-iii. A fix is available for grumpydictator/firefly-iii — see the affected versions and patch details below.
Real-World Exposure
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
Summary
CSV injection is a vulnerability where untrusted user input in CSV files can lead to unauthorized access or data manipulation. In my subsequent testing of the application.
Details
I discovered that there is an option to "Export Data" from the web app to your personal computer, which exports a "csv" file that can be opened with Excel software that supports macros.
P.S I discovered that the web application's is offering a demo-site that anyone may access to play with the web application. So, there's a chance that someone will export the data (CVS) from the demo site and execute it on their PC, giving the malicious actor a complete control over their machine. (if a user enters a malicious payload to the website).
PoC
You can check out my vulnerability report if you need more details/PoC with screenshots: (removed by JC5)
Impact
An attacker can exploit this by entering a specially crafted payload to one of the fields, and when a user export the csv file using the "Export Data" function, the attacker can potentiality can RCE.
Addendum by JC5, the developer of Firefly III
There is zero impact on normal users, even on vulnerable versions.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | grumpydictator/firefly-iii | all versions | 6.1.7composer require grumpydictator/firefly-iii:^6.1.7 |
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, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update grumpydictator/firefly-iii to 6.1.7 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-29w6-c52g-m8jc 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.
Frequently Asked Questions
Is GHSA-29w6-c52g-m8jc in your dependencies?
Find it across Packagist, including transitive dependencies.