GHSA-V3Q9-2P3M-7G43
Vulnerability from github – Published: 2021-05-24 16:57 – Updated: 2023-08-29 23:07Impact
When using client authentication method "private_key_jwt" [1], 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
{
"affected": [
{
"package": {
"ecosystem": "Go",
"name": "github.com/ory/fosite"
},
"ranges": [
{
"events": [
{
"introduced": "0"
},
{
"fixed": "0.31.0"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2020-15222"
],
"database_specific": {
"cwe_ids": [
"CWE-287",
"CWE-345"
],
"github_reviewed": true,
"github_reviewed_at": "2021-05-24T12:52:00Z",
"nvd_published_at": "2020-09-24T17:15:00Z",
"severity": "HIGH"
},
"details": "### Impact\n\nWhen 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`:\n\n\u003e 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\n\nHydra 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:\n\n```\n$ curl --insecure --location --request POST \u0027https://localhost/_/oauth2/token\u0027 \\\n --header \u0027Content-Type: application/x-www-form-urlencoded\u0027 \\\n --data-urlencode \u0027grant_type=client_credentials\u0027 \\\n --data-urlencode \u0027client_id=c001d00d-5ecc-beef-ca4e-b00b1e54a111\u0027 \\\n --data-urlencode \u0027scope=application openid\u0027 \\\n --data-urlencode \u0027client_assertion_type=urn:ietf:params:oauth:client-assertion-type:jwt-bearer\u0027 \\\n --data-urlencode \u0027client_assertion=eyJhb [...] jTw\u0027\n{\"access_token\":\"zeG0NoqOtlACl8q5J6A-TIsNegQRRUzqLZaYrQtoBZQ.VR6iUcJQYp3u_j7pwvL7YtPqGhtyQe5OhnBE2KCp5pM\",\"expires_in\":3599,\"scope\":\"application openid\",\"token_type\":\"bearer\"}\u23ce\n$ curl --insecure --location --request POST \u0027https://localhost/_/oauth2/token\u0027 \\\n --header \u0027Content-Type: application/x-www-form-urlencoded\u0027 \\\n --data-urlencode \u0027grant_type=client_credentials\u0027 \\\n --data-urlencode \u0027client_id=c001d00d-5ecc-beef-ca4e-b00b1e54a111\u0027 \\\n --data-urlencode \u0027scope=application openid\u0027 \\\n --data-urlencode \u0027client_assertion_type=urn:ietf:params:oauth:client-assertion-type:jwt-bearer\u0027 \\\n --data-urlencode \u0027client_assertion=eyJhb [...] jTw\u0027\n{\"access_token\":\"wOYtgCLxLXlELORrwZlmeiqqMQ4kRzV-STU2_Sollas.mwlQGCZWXN7G2IoegUe1P0Vw5iGoKrkOzOaplhMSjm4\",\"expires_in\":3599,\"scope\":\"application openid\",\"token_type\":\"bearer\"}\n```\n\n### Patches\n\nThis issue is patched in 0.31.0.\n\n### Workarounds\n\nDo not allow clients to use `private_key_jwt`.\n\n### References\n\nhttps://openid.net/specs/openid-connect-core-1_0.html#ClientAuthentication",
"id": "GHSA-v3q9-2p3m-7g43",
"modified": "2023-08-29T23:07:22Z",
"published": "2021-05-24T16:57:52Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/ory/fosite/security/advisories/GHSA-v3q9-2p3m-7g43"
},
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2020-15222"
},
{
"type": "WEB",
"url": "https://github.com/ory/fosite/commit/0c9e0f6d654913ad57c507dd9a36631e1858a3e9"
},
{
"type": "PACKAGE",
"url": "https://github.com/ory/fosite"
},
{
"type": "WEB",
"url": "https://github.com/ory/fosite/releases/tag/v0.31.0"
},
{
"type": "WEB",
"url": "https://openid.net/specs/openid-connect-core-1_0.html#ClientAuthentication"
},
{
"type": "WEB",
"url": "https://pkg.go.dev/vuln/GO-2021-0110"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/A:N",
"type": "CVSS_V3"
}
],
"summary": "Token reuse in Ory fosite"
}
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