Cyber Resilience

CVE-2021-46743

CriticalPublic PoC

Published: 29 March 2022

Published
29 March 2022
Modified
21 November 2024
KEV Added
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Patch
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CVSS Score v3.1 9.1 CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N
EPSS Score 0.0064 71.1th percentile
Risk Priority 19 60% EPSS · 20% KEV · 20% CVSS

Summary

CVE-2021-46743 is a critical-severity Type Confusion (CWE-843) vulnerability in Google Firebase Php-Jwt. Its CVSS base score is 9.1 (Critical).

Operationally, ranked in the top 28.9% of CVEs by exploit likelihood; it is not currently listed in the CISA KEV catalog; a public proof-of-concept is referenced.

EU & UK References

Vulnerability details

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…

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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.

CWE(s)
CWE-843

Related Threats

No named actor attribution yet. ATT&CK technique mapping in progress for this CVE.

Affected Assets

google
firebase php-jwt
≤ 6.0.0

Mitigating Controls

No mitigating controls mapped yet. The per-CVE control annotator has not reached this CVE.

References