Auth bypass in React-Adal Project
CVE-2020-7787
This affects all versions of package react-adal. 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.
Vulnerability class: Broken Authentication
Published · last modified .
CVSS v3 metric
CVSS v3 base score 8.2 (High). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N.
EPSS exploit prediction
EPSS: 0.013 (69.0th percentile), scored .
Low probability of exploitation in the next 30 days, but still tracked. 69th percentile — 69.0% of CVEs in the catalogue have a lower EPSS than this one. How to read EPSS.
EPSS over last 30 days · oldest: 0.013 · newest: 0.013 · change: 0.000
Affected products
- React-Adal Project
- React-Adal — versions 0
Weakness classification (CWE)
References
- snyk.io/vuln/SNYK-JS-REACTADAL-1018907 (Exploit, Third Party Advisory)
- github.com/salvoravida/react-adal/pull/115 (Exploit, Third Party Advisory)
Frequently asked questions
- What is CVE-2020-7787?
- CVE-2020-7787 is a high-severity vulnerability in React-Adal Project, classified under Improper Authentication. CVSS score: 8.2/10. Published 2020-12-09.
- How severe is CVE-2020-7787?
- High severity. CVSS v3 base score is 8.2 out of 10.