CVE-2020-15223: 
vulnerability analysis and mitigation

CVE-2020-15223 affects ORY Fosite, an OAuth2 & OpenID Connect framework for Go, in versions before 0.34.0. The vulnerability was discovered and disclosed on September 24, 2020. The issue affects the TokenRevocationHandler component which incorrectly handles storage errors during token revocation operations (GitHub Advisory).

The vulnerability exists in the TokenRevocationHandler component which ignores errors coming from the storage layer during token revocation operations. When errors occur during the revocation process, the handler incorrectly returns a 200 status code indicating successful revocation while the token remains valid. The issue was assigned a CVSS v3.1 Base Score of 8.0 HIGH with vector CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:C/C:H/I:H/A:N (NVD).

This vulnerability can lead to unexpected 200 status codes indicating successful token revocation while the token actually remains valid and usable. The impact severity depends on an attacker's ability to trigger errors in the storage layer. When storage errors occur, tokens that should be invalidated remain active, potentially allowing continued unauthorized access (GitHub Advisory).

The exploitability of this vulnerability depends on the ability to trigger errors in the underlying storage implementation. According to RFC 7009, when server errors occur during token revocation, a 503 HTTP status code should be returned to indicate the server is temporarily unavailable (RFC 7009).

The vulnerability was fixed in version 0.34.0 of ORY Fosite. The fix properly handles storage errors during token revocation and returns appropriate error responses. No workarounds are available for affected versions - upgrading to v0.34.0 or later is required (GitHub Advisory).