// For flags

CVE-2024-23647

PKCE downgrade attack in Authentik

Severity Score

8.8
*CVSS v3.1

Exploit Likelihood

*EPSS

Affected Versions

*CPE

Public Exploits

0
*Multiple Sources

Exploited in Wild

-
*KEV

Decision

-
*SSVC
Descriptions

Authentik is an open-source Identity Provider. There is a bug in our implementation of PKCE that allows an attacker to circumvent the protection that PKCE offers. PKCE adds the code_challenge parameter to the authorization request and adds the code_verifier parameter to the token request. Prior to 2023.8.7 and 2023.10.7, a downgrade scenario is possible: if the attacker removes the code_challenge parameter from the authorization request, authentik will not do the PKCE check. Because of this bug, an attacker can circumvent the protection PKCE offers, such as CSRF attacks and code injection attacks. Versions 2023.8.7 and 2023.10.7 fix the issue.

Authentik es un proveedor de identidades de código abierto. Hay un error en nuestra implementación de PKCE que permite a un atacante eludir la protección que ofrece PKCE. PKCE agrega el parámetro code_challenge a la solicitud de autorización y agrega el parámetro code_verifier a la solicitud de token. Antes de 2023.8.7 y 2023.10.7, es posible un escenario de degradación: si el atacante elimina el parámetro code_challenge de la solicitud de autorización, authentik no realizará la verificación PKCE. Debido a este error, un atacante puede eludir la protección que ofrece PKCE, como los ataques CSRF y los ataques de inyección de código. Las versiones 2023.8.7 y 2023.10.7 solucionan el problema.

*Credits: N/A
CVSS Scores
Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
Required
Scope
Unchanged
Confidentiality
High
Integrity
High
Availability
High
Attack Vector
Network
Attack Complexity
Low
Privileges Required
None
User Interaction
Required
Scope
Unchanged
Confidentiality
None
Integrity
High
Availability
None
* Common Vulnerability Scoring System
SSVC
  • Decision:-
Exploitation
-
Automatable
-
Tech. Impact
-
* Organization's Worst-case Scenario
Timeline
  • 2024-01-19 CVE Reserved
  • 2024-01-30 CVE Published
  • 2024-02-08 EPSS Updated
  • 2024-08-01 CVE Updated
  • ---------- Exploited in Wild
  • ---------- KEV Due Date
  • ---------- First Exploit
CWE
  • CWE-287: Improper Authentication
CAPEC
Affected Vendors, Products, and Versions
Vendor Product Version Other Status
Vendor Product Version Other Status <-- --> Vendor Product Version Other Status
Goauthentik
Search vendor "Goauthentik"
 Authentik
Search vendor "Goauthentik" for product "Authentik"
 < 2023.8.7
Search vendor "Goauthentik" for product "Authentik" and version " < 2023.8.7"
-
Affected
Goauthentik
Search vendor "Goauthentik"
 Authentik
Search vendor "Goauthentik" for product "Authentik"
 >= 2023.10.0 < 2023.10.7
Search vendor "Goauthentik" for product "Authentik" and version " >= 2023.10.0 < 2023.10.7"
-
Affected