PT-2020-19791 · Microsoft · React-Adal
Kris Hardy
·
Published
2020-12-09
·
Updated
2021-04-13
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CVE-2020-7787
CVSS v3.1
8.2
High
| Vector | AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:L/A:N |
Name of the Vulnerable Software and Affected Versions
react-adal versions prior to 0.5.1
Description
The issue arises from 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.
Recommendations
For versions prior to 0.5.1, update to version 0.5.1 or later to resolve the issue. As a temporary workaround, consider restricting the use of the vulnerable component until a patch is available. Avoid using an empty session parameter in the callback URL and ensure that JWT tokens do not contain an empty string as the nonce value.
Exploit
Fix
Improper Authentication
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Weakness Enumeration
Related Identifiers
Affected Products
React-Adal