CVE-2019-20455 is a medium-severity (CVSS 5.9) CWE-295 vulnerability in globalpayments/php-sdk. 2 public exploit references exist, so weaponization risk is real. A fix is available for globalpayments/php-sdk — see the affected versions and patch details below.
Improper Certificate Validation in Heartland & Global Payments PHP SDK
EPSS Exploitation Probability
Probability of exploitation in the next 30 days, from FIRST.org EPSS.
How urgent is this, really
CVE-2019-20455 by exploitation likelihood (EPSS) against impact (CVSS). Outside the shaded patch-first corner.
Where this sits among everything scored
Of 385,987 CVEs with a current EPSS score, this one falls in the < 10% band (highlighted). Counts from FIRST.org, log-scaled.
Real-World Exposure
globalpayments/php-sdkReal-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
Gateways/Gateway.php in Heartland & Global Payments PHP SDK before 2.0.0 does not enforce SSL certificate validations.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | globalpayments/php-sdk | all versions | 2.0.0composer require globalpayments/php-sdk:^2.0.0 |
Affected Products
php sdkglobalpaymentsResearch 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 globalpayments/php-sdk, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update globalpayments/php-sdk to 2.0.0 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2019-20455 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.
Frequently Asked Questions
Is CVE-2019-20455 in your dependencies?
Find it across Packagist, including transitive dependencies.