Attacker Value
Unknown
(0 users assessed)
Exploitability
Unknown
(0 users assessed)
User Interaction
None
Privileges Required
None
Attack Vector
Network
0

CVE-2023-48223

Disclosure Date: November 20, 2023
Add MITRE ATT&CK tactics and techniques that apply to this CVE.

Description

fast-jwt provides fast JSON Web Token (JWT) implementation. Prior to version 3.3.2, the fast-jwt library does not properly prevent JWT algorithm confusion for all public key types. The ‘publicKeyPemMatcher’ in ‘fast-jwt/src/crypto.js’ does not properly match all common PEM formats for public keys. To exploit this vulnerability, an attacker needs to craft a malicious JWT token containing the HS256 algorithm, signed with the public RSA key of the victim application. This attack will only work if the victim application utilizes a public key containing the BEGIN RSA PUBLIC KEY header. Applications using the RS256 algorithm, a public key with a BEGIN RSA PUBLIC KEY header, and calling the verify function without explicitly providing an algorithm, are vulnerable to this algorithm confusion attack which allows attackers to sign arbitrary payloads which will be accepted by the verifier. Version 3.3.2 contains a patch for this issue. As a workaround, change line 29 of blob/master/src/crypto.js to include a regular expression.

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CVSS V3 Severity and Metrics
Base Score:
5.9 Medium
Impact Score:
3.6
Exploitability Score:
2.2
Vector:
CVSS:3.1/AV:N/AC:H/PR:N/UI:N/S:U/C:N/I:H/A:N
Attack Vector (AV):
Network
Attack Complexity (AC):
High
Privileges Required (PR):
None
User Interaction (UI):
None
Scope (S):
Unchanged
Confidentiality (C):
None
Integrity (I):
High
Availability (A):
None

General Information

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Additional Info

Technical Analysis