VulnerabilityModified
CVE-2021-46743
This allows an attacker to forge tokens that validate under the incorrect key.
CRITICAL 9.1EPSS 0.79%
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.79%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
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.
- CVSS 3.1
- 9.1 CRITICALCVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
- EPSS
- 0.79% probability · 54th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-843
- Affected
- google/firebase php-jwt
- Source
- cve@mitre.org
References
- https://github.com/firebase/php-jwt/issues/351Exploit, Third Party Advisory
- https://github.com/firebase/php-jwt/issues/351Exploit, Third Party Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.