GHSA-2xmm-m4wv-3fjh
LOWGHSA-2xmm-m4wv-3fjh is a low-severity (CVSS 3.9) remote code execution vulnerability in october/october. O3 Security confirms whether GHSA-2xmm-m4wv-3fjh is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
October CMS: Incomplete Scheme Validation in Image Resizer
Real-World Exposure
october/octoberReal-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
The image resizer classified external sources by testing whether the source string began with the substring http, and the string-source branch in ResizeImageItem::fromObject() accepted any value containing :// as a URL. As a result, non-http(s) PHP stream wrappers such as phar://, file:// and ftp:// could be stored in the resizer cache and later passed to the underlying image library. On a phar:// path this can lead to metadata deserialization during subsequent file operations.
Exploitation requires an existing template-authoring or backend-configuration primitive that passes untrusted input into the |resize Twig filter (or the ResizeImages::resize() API). The /resize/{file} route itself is a lookup against a cache entry that was previously written by trusted server-side code, and an unauthenticated visitor cannot cause an arbitrary source path to be written into that cache. In October's trust model the Publisher and Developer backend roles that can author templates are already trusted with template code execution, so this is a defense-in-depth hardening rather than an unauthenticated network-to-RCE path.
Impact
- On installations where a template author has piped untrusted input into
|resizewithout validation, aphar://source could reach the resizer and trigger metadata deserialization - No exposure on default templates or on installations where
|resizeis only applied to trusted values (uploaded file models, theme assets, static URLs) - Hardening; not exploitable from the network without a pre-existing injection primitive on the calling code
Patches
The vulnerability has been patched in v4.3.5.
Workarounds
If upgrading immediately is not possible:
- Audit template code and backend widget configuration for uses of the
|resizefilter (or directResizeImages::resize()calls) that accept untrusted string input, and validate the scheme ishttp/httpsbefore passing it in
References
- Reported by 0xGenesi
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | october/october | ≥ 4.3.0&&< 4.3.5 | 4.3.5 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for october/october. 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 october/october to 4.3.5 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-2xmm-m4wv-3fjh 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-2xmm-m4wv-3fjh 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-2xmm-m4wv-3fjh. 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-2xmm-m4wv-3fjh in your dependencies?
O3 detects GHSA-2xmm-m4wv-3fjh across Packagist dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.