CVE-2021-30134 is a medium-severity (CVSS 6.1) Cross-site Scripting (XSS) vulnerability in php-mod/curl. 1 public exploit or proof-of-concept reference is indexed, so weaponization risk is real. A fix is available for php-mod/curl — see the affected versions and patch details below.
php-mod/curl allows Cross-site Scripting
Exploitation Status
Proof-of-concept exploit code exists
- CISA’s SSVC triage found public proof-of-concept exploit code for this CVE, though no confirmed active exploitation.
Exploitation and automatability from CISA’s SSVC triage for CVE-2021-30134.
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
Where this sits among everything scored
Real-World Exposure
php-mod/curlReal-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
php-mod/curl (a wrapper of the PHP cURL extension) before 2.3.2 allows XSS via the post_file_path_upload.php key parameter and the POST data to post_multidimensional.php.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | php-mod/curl | all versions | 2.3.2composer require php-mod/curl:^2.3.2 |
Affected Products
ht slider range for amazon affiliatesht_slider_range_for_amazon_affiliates_projectphp curl classphp_curl_class_projectinvoicing with invoicexpress for woocommerceptwoopluginswoo-qiwi-payment-gatewayqiwishopello apishopello_api_projectteamleader crm formsteamleadeResearch use only. For defensive security, authorized penetration testing, and academic research only. Never execute exploit code against systems without explicit written authorization.
Detection & mitigation playbook
Open-source dependencyDetect
Scan your dependency tree (package-lock.json, pnpm-lock.yaml, requirements.txt, go.sum, etc.) for php-mod/curl, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update php-mod/curl to 2.3.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2021-30134 is resolved across your whole dependency graph.
Workarounds
Escape or sanitise the affected output on the server side rather than relying on client-side filtering, and add a Content-Security-Policy that blocks inline script execution so injected markup cannot run even if it reaches the page.
How to detect CVE-2021-30134
A community-maintained Nuclei template exists for this CVE. You can scan for it directly:
nuclei -id cve-2021-30134 -u https://target- Template
- Php-mod/curl Library <2.3.2 - Cross-Site Scripting
- Severity
- medium
- Impact
- Successful exploitation of this vulnerability could allow an attacker to inject malicious scripts into web pages viewed by users, leading to potential data theft, session hijacking, or defacement.
- Remediation
- Upgrade to Php-mod/curl Library version 2.3.2 or later to mitigate the vulnerability.
Template by ProjectDiscovery nuclei-templates (theamanrawat), MIT licensed. View the full template. Scan only systems you are authorised to test.
Frequently Asked Questions
Is CVE-2021-30134 in your dependencies?
Find it across Packagist, including transitive dependencies.