GHSA-2h87-4q2w-v4hf
CRITICALStrapi plugins vulnerable to Server-Side Template Injection and Remote Code Execution in the Users-Permissions Plugin
EPSS Exploitation Probability
EPSS (Exploit Prediction Scoring System) is a daily probability model maintained by FIRST.org. It estimates the likelihood a CVE will be exploited in production environments within the next 30 days, derived from real-world threat intelligence signals.
Blast Radius
@strapi/plugin-users-permissions📦@strapi/plugin-emailReal-time download stats are indexed for npm and PyPI packages. This vulnerability affects npm packages — download data is not available via public APIs for these ecosystems.
Description
Summary
Strapi through 4.5.5 allows authenticated Server-Side Template Injection (SSTI) that can be exploited to execute arbitrary code on the server.
Details
Strapi through 4.5.5 allows authenticated Server-Side Template Injection (SSTI) that can be exploited to execute arbitrary code on the server. A remote attacker with access to the Strapi admin panel can inject a crafted payload that executes code on the server into an email template that bypasses the validation checks that should prevent code execution.
IoC
Using just the request log files, the only IoC to search for is a PUT request to URL path /users-permissions/email-templates. This IoC only indicates that a Strapi email template was modified on your server and by itself does not indicate if your Strapi server has been compromised. If this IoC is detected, you will need to manually review your email templates on your Strapi server and backups of your database to see if any of the templates contain a lodash template delimiter (eg. <%STUFF HERE%>) that contains suspicious JavaScript code. Generally speaking these templates should look like the following, you may have minor adjustments but any unrecognized code should be considered suspicious.
Reset Password Template:
<p>We heard that you lost your password. Sorry about that!</p>
<p>But don’t worry! You can use the following link to reset your password:</p>
<p><%= URL %>?code=<%= TOKEN %></p>
<p>Thanks.</p>
Email Confirmation Template:
<p>Thank you for registering!</p>
<p>You have to confirm your email address. Please click on the link below.</p>
<p><%= URL %>?confirmation=<%= CODE %></p>
<p>Thanks.</p>
Specifically you should look for odd code contained within the <%STUFF HERE%> blocks as this is what is used to bypass the lodash templating system. If you find any code that is not a variable name, or a variable name that is not defined in the template you are most likely impacted and should take immediate steps to confirm there are no malicious applications running on your servers.
Impact
All users on Strapi below 4.5.6 with access to the admin panel and the ability to modify the email templates
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | @strapi/plugin-users-permissions | all versions | 4.5.6 |
| 📦npm | @strapi/plugin-email | all versions | 4.5.6 |
Research use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
Frequently Asked Questions
Is GHSA-2h87-4q2w-v4hf in your stack?
O3 detects GHSA-2h87-4q2w-v4hf across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.