GHSA-rf2p-vh74-7vvh
Fix: getkirby/kirby@469c5a1GHSA-rf2p-vh74-7vvh is a CWE-497 vulnerability in getkirby/cms. O3 Security confirms whether GHSA-rf2p-vh74-7vvh is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Kirby: System path exposure from error messages in the REST API
Real-World Exposure
getkirby/cms🐘getkirby/cmsReal-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
TL;DR
This vulnerability affects all Kirby sites that have not disabled the REST API with the 'api' => false option.
It was possible to trigger a PHP error in the API backend that would expose the full filesystem path of the Kirby installation on the server. This could be used to guess the default content.salt or prepare specialized attacks.
Introduction
An information exposure occurs when system data or debugging information leaves the program through an output stream or logging function that makes it accessible to unauthorized parties. Using other weaknesses, an attacker could cause errors to occur; the response to these errors can reveal detailed system information, along with other impacts. An attacker can use messages that reveal technologies, operating systems, and product versions to tune the attack against known vulnerabilities in these technologies. A product may use diagnostic methods that provide significant implementation details such as stack traces as part of its error handling mechanism.
Affected components
Kirby's REST API at /api returns JSON data for each request. If an error occurs during processing of the request, a special error handler converts this error to JSON data that API frontends can handle.
The returned data for errors depends on the debugging mode. If the debug option is enabled, the JSON data contains fields for the path and line of the affected file, the internal exception class and the API route that caused the error. This data is omitted from error responses in production (when the debug option is disabled).
Impact
Some internal errors may contain sensitive information in the error message itself. This is often the case with PHP errors.
In affected releases, the REST API error handler did not sanitize error messages for sensitive information.
This exposed system information like the full source path to external API users, including users without authentication. This could be used to guess the default content.salt or prepare specialized attacks.
Patches
The problem has been patched in Kirby 4.9.5 and Kirby 5.5.2. Please update to one of these or a later version to fix the vulnerability.
In all of the mentioned releases, Kirby has hardened the API error handler to only expose full error messages for exceptions in the Kirby\Exception namespace. All other errors are only exposed in debug mode (with disguised paths, keeping only the paths relative to the Kirby installation). Outside of debug mode, general exceptions and PHP errors are replaced with a generic error message.
Credits
Thanks to Peter Levashov (@petersevera) for responsibly reporting the identified issue.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | getkirby/cms | all versions | 4.9.5 |
| 🐘Packagist | getkirby/cms | ≥ 5.0.0&&< 5.5.2 | 5.5.2 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for getkirby/cms. 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 getkirby/cms to 4.9.5 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-rf2p-vh74-7vvh 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-rf2p-vh74-7vvh 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-rf2p-vh74-7vvh. 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-rf2p-vh74-7vvh in your dependencies?
O3 detects GHSA-rf2p-vh74-7vvh across Packagist dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.