Description

Spring Authorization Server versions 1.0.0 - 1.0.5, 1.1.0 - 1.1.5, 1.2.0 - 1.2.2 and older unsupported versions are susceptible to a PKCE Downgrade Attack for Confidential Clients.

Specifically, an application is vulnerable when a Confidential Client uses PKCE for the Authorization Code Grant.

An application is not vulnerable when a Public Client uses PKCE for the Authorization Code Grant.

Affected Spring Products and Versions

Spring Authorization Server

• 1.0.0 - 1.0.5
• 1.1.0 - 1.1.5
• 1.2.0 - 1.2.2
• Older, unsupported versions are also affected

Mitigation

Users of affected versions should upgrade to the corresponding fixed version.

Credit

This issue was identified and responsibly reported by Pieter Philippaerts ([email protected]).

References

• https://nvd.nist.gov/vuln-metrics/cvss/v3-calculator?vector=AV:N/AC:L/PR:N/UI:R/S:C/C:L/I:L/A:N/E:F/RL:O/RC:C/CR:L/IR:L/AR:X/MAV:N/MAC:L/MPR:N/MUI:R/MS:C/MC:L/MI:L/MA:N&version=3.1
• https://cwe.mitre.org/data/definitions/287.html