CVE-2020-7787 is a high-severity (CVSS 8.2) Improper Authentication vulnerability in react-adal. 2 public exploit references exist, so weaponization risk is real. O3 Security confirms whether CVE-2020-7787 is actually reachable in your code before you act, and blocks exploitation at runtime until you patch.
Improper Authentication in react-adal
Real-World Exposure
react-adalReal-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
This affects versions of react-adal < 0.5.1. It is possible for a specially crafted JWT token and request URL can cause the nonce, session and refresh values to be incorrectly validated, causing the application to treat an attacker-generated JWT token as authentic. The logical defect is caused by how the nonce, session and refresh values are stored in the browser local storage or session storage. Each key is automatically appended by ||. When the received nonce and session keys are generated, the list of values is stored in the browser storage, separated by ||, with || always appended to the end of the list. Since || will always be the last 2 characters of the stored values, an empty string ("") will always be in the list of the valid values. Therefore, if an empty session parameter is provided in the callback URL, and a specially-crafted JWT token contains an nonce value of "" (empty string), then adal.js will consider the JWT token as authentic.
Affected Packages
| Ecosystem | Package | Vulnerable range | Fix |
|---|---|---|---|
| 📦npm | react-adal | all versions | 0.5.1 |
Research 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 react-adal. 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 react-adal to 0.5.1 or later, then make sure no transitive (indirect) dependency still pins the vulnerable range — O3 confirms CVE-2020-7787 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 CVE-2020-7787 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 CVE-2020-7787. Runtime protection reduces exposure until a permanent patch is applied and verified — it complements patching, it doesn't replace it.
Frequently Asked Questions
Is CVE-2020-7787 in your dependencies?
O3 detects CVE-2020-7787 across npm dependencies and uses function-level reachability to confirm whether the vulnerable code path is actually reachable — not just present. No false positives.