CVE-2024-23647 json
PKCE downgrade attack in Authentik
published 2024-01-29 2 y ago modified 2026-09-10 1 mo ago also BIT-authentik-2024-23647 , EUVD-2024-0389 , GHSA-mrx3-gxjx-hjqj , GO-2024-2479
- cvss
- 6.5
- version 3.1, CNA
- cisa kev
- Not listed
- not in CISA's catalog
- epss
- 0.5%
- EPSS 0.5% chance of exploitation in 30 days, percentile 46%
- public exploits
- 0
- none known
Summary
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.
Patch / fix
- go goauthentik.io 2023.8.7, 2023.10.7
- bitnami authentik 2023.8.7, 2023.10.7
- goauthentik authentik 2023.8.7, 2023.10.7
CISA SSVC
- Exploitation
- none
- Automatable
- no
- Technical impact
- total
- Assessed
- 2 y ago
Exploit prediction
0.55% chance of exploitation in the next 30 days, higher than 46% of all scored CVEs (FIRST EPSS, 2026-11-08).
CVSS scores
| assigned by | version | score | vector |
|---|---|---|---|
| CNA | 3.1 | 6.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N |
| GitHub | 3.1 | 6.5 | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:N/I:H/A:N |
| NVD | 3.1 | 8.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H |
| OSV | 3.1 | 8.8 | CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H |
Affected packages
| ecosystem | package | affected | fixed in |
|---|---|---|---|
| go | goauthentik.io | >=2023.10.0, <2023.10.7 <2023.8.7 all versions |
2023.10.7 2023.8.7 |
| bitnami | authentik | <2023.8.7 >=2023.10.0, <2023.10.7 |
2023.8.7 2023.10.7 |
Affected products
- goauthentik authentik
Classification
- Weakness
-
- CWE-287 Improper Authentication
References
-
github.com
/goauthentik/authentik/commit/38e04ae12720e5d81b4f7ac77997eb8d1275d31a
web, patch
-
github.com
/goauthentik/authentik/security/advisories/GHSA-mrx3-gxjx-hjqj
web, third-party-advisory, advisory
-
nvd.nist.gov
/vuln/detail/CVE-2024-23647
advisory, web
-
github.com
/goauthentik/authentik
package
Sources
- CVE List CVE-2024-23647
- GitHub Advisory GHSA-mrx3-gxjx-hjqj
- NVD CVE-2024-23647
- OSV BIT-authentik-2024-23647
- OSV GO-2024-2479
Fencer Vulns keeps one entry per vulnerability: the CVE id wins, then GHSA, and records that alias each other are merged, except that two CVEs always keep separate entries. The same data is available as JSON.