Vulnerability in Google Firebase Php-Jwt
CVE-2021-46743
In Firebase PHP-JWT before 6.0.0, an algorithm-confusion issue (e.g., RS256 / HS256) exists via the kid (aka Key ID) header, when multiple types of keys are loaded in a key ring. This allows an attacker to forge tokens that validate under the incorrect key. NOTE: this provides a straightforward way to use the PHP-JWT library unsafely, but might not be considered a vulnerability in the library itself.
EPSS: 0.008 (52.1th percentile) — read the EPSS interpretation.
CVSS v3 metric
CVSS v3 base score 9.1 (Critical). Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N.
Affected products
- Google Firebase_php-jwt
- N/a — versions n/a
Weakness classification (CWE)
Public proof-of-concept exploits
References
- cve@mitre.org (Exploit, Third Party Advisory, x_refsource_MISC)
Frequently asked questions
- What is CVE-2021-46743?
- CVE-2021-46743 is a critical-severity vulnerability in Google Firebase Php-Jwt, classified under Access of Resource Using Incompatible Type (Type Confusion). CVSS score: 9.1/10. Published 2022-03-29.
- How severe is CVE-2021-46743?
- Critical severity. CVSS v3 base score is 9.1 out of 10.
- Is CVE-2021-46743 known to be exploited?
- 1 public proof-of-concept repositories are indexed. Not currently listed in the CISA KEV catalog.