CVE-2024-23647
There is a bug in our implementation of PKCE that allows an attacker to circumvent the protection that PKCE offers.
Does this matter?
High impact if exploited, but EPSS currently rates exploitation as unlikely (0.54%). Schedule it in the normal patch cycle and watch for a rise in EPSS or a public exploit.
Description
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.
- CVSS 3.1
- 8.8 HIGHCVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:H
- EPSS
- 0.54% probability · 44th percentile
- CISA KEV
- Not listed
- Weakness
- CWE-287
- Affected
- goauthentik/authentik
- Source
- security-advisories@github.com
References
- https://github.com/goauthentik/authentik/commit/38e04ae12720e5d81b4f7ac77997eb8d1275d31aPatch
- https://github.com/goauthentik/authentik/security/advisories/GHSA-mrx3-gxjx-hjqjThird Party Advisory
- https://github.com/goauthentik/authentik/commit/38e04ae12720e5d81b4f7ac77997eb8d1275d31aPatch
- https://github.com/goauthentik/authentik/security/advisories/GHSA-mrx3-gxjx-hjqjThird Party Advisory
Source: NVD record, EPSS from FIRST.org, KEV from CISA. Refreshed daily.