CVE-2020-36655 is a high-severity (CVSS 8.8) Code Injection vulnerability in yiisoft/yii2-gii. 2 public exploit or proof-of-concept references are indexed, so weaponization risk is real. A fix is available for yiisoft/yii2-gii — see the affected versions and patch details below.
Command injection in yiisoft/yii2-gii
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.
- A successful exploit gives an attacker total control of the affected component, not partial access.
Exploitation and automatability from CISA’s SSVC triage for CVE-2020-36655.
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
yiisoft/yii2-giiReal-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
Yii Yii2 Gii before 2.2.2 allows remote attackers to execute arbitrary code via the Generator.php messageCategory field. The attacker can embed arbitrary PHP code into the model file.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 🐘Packagist | yiisoft/yii2-gii | all versions | 2.2.2composer require yiisoft/yii2-gii:^2.2.2 |
Affected Products
giiyiiframeworkResearch 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 yiisoft/yii2-gii, including transitive dependencies — a direct dependency you never call can still pull in a vulnerable version.
Fix
Update yiisoft/yii2-gii to 2.2.2 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2020-36655 is resolved across your whole dependency graph.
Workarounds
Stop passing untrusted input into the interpreter or shell: call the affected binary with an argument array rather than a composed command string, reject anything outside a strict allowlist of expected values, and run the component under an account that cannot reach beyond the work it legitimately does.
Frequently Asked Questions
Is CVE-2020-36655 in your dependencies?
Find it across Packagist, including transitive dependencies.