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.

• CVE ID
• CVE-2021-46743

• Assigner
• cve@mitre.org

• Vulnerability Status
• Analyzed

• Published Version
• 2022-03-29T07:15:07

• Last Modified Date
• 2022-04-08T15:14:50

• Version
• 2.0

• Vector String
• AV:N/AC:M/Au:N/C:P/I:P/A:N

• Access Vector
• NETWORK

• Access Compatibility
• MEDIUM

• Authentication
• NONE

• Confidentiality Impact
• PARTIAL

• Integrity Impact
• PARTIAL

• Availability Impact
• NONE

• Base Score
• 5.8

• Severity
• MEDIUM

• Exploitability Score
• 8.6

• Impact Score
• 4.9

• Version
• 3.1

• Vector String
• CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:H/I:H/A:N

• Attack Vector
• NETWORK

• Attack Compatibility
• LOW

• Privileges Required
• NONE

• User Interaction
• NONE

• Scope
• UNCHANGED

• Confidentiality Impact
• HIGH

• Availability Impact
• NONE

• Base Score
• 9.1

• Base Severity
• CRITICAL

• Exploitability Score
• 3.9

• Impact Score
• 5.2