GHSA-V9XQ-2MVM-X8XC
Vulnerability from github – Published: 2024-10-28 19:44 – Updated: 2024-10-28 21:49Impact
IdentityServer's local API authentication handler performs insufficient validation of the cnf claim in DPoP access tokens. This allows an attacker to use leaked DPoP access tokens at local api endpoints even without possessing the private key for signing proof tokens.
Note that this only impacts custom endpoints within an IdentityServer implementation that have explicitly used the LocalApiAuthenticationHandler for authentication. It does not impact:
- OAuth or OIDC protocol endpoints defined by IdentityServer, such as the authorize and token endpoints.
- Typical UI pages within an IdentityServer implementation, which are not normally authorized with the local API authentication handler.
- The use of DPoP to create sender-constrained tokens in IdentityServer that are consumed by external API resources.
- The use of DPoP to sender-constrain refresh tokens issued to public clients.
Are you affected?
This vulnerability only affects IdentityServer implementations that are using the local APIs feature of IdentityServer and have explicitly enabled DPoP for local APIs. The local api authentication handler is configured with a call to either AddLocalApi or AddLocalApiAuthentication, and the opt-in to DPoP for local APIs is enabled via the TokenMode option.
Vulnerable implementations of IdentityServer would have configuration code similar to the following:
services.AddAuthentication()
.AddLocalApi("local", options =>
{
options.TokenMode = LocalApiTokenMode.DPoPAndBearer; // or LocalApiTokenMode.DPoPOnly
});
Patches
This vulnerability is patched in IdentityServer 7.0.8. Version 6.3 and below are unaffected, as they do not support DPoP in Local APIs.
{
"affected": [
{
"package": {
"ecosystem": "NuGet",
"name": "Duende.IdentityServer"
},
"ranges": [
{
"events": [
{
"introduced": "7.0.0"
},
{
"fixed": "7.0.8"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2024-49755"
],
"database_specific": {
"cwe_ids": [
"CWE-287"
],
"github_reviewed": true,
"github_reviewed_at": "2024-10-28T19:44:10Z",
"nvd_published_at": "2024-10-28T20:15:06Z",
"severity": "LOW"
},
"details": "### Impact\nIdentityServer\u0027s local API authentication handler performs insufficient validation of the `cnf` claim in DPoP access tokens. This allows an attacker to use leaked DPoP access tokens at local api endpoints even without possessing the private key for signing proof tokens.\n\nNote that this only impacts custom endpoints within an IdentityServer implementation that have explicitly used the `LocalApiAuthenticationHandler` for authentication. It does not impact:\n- OAuth or OIDC protocol endpoints defined by IdentityServer, such as the authorize and token endpoints.\n- Typical UI pages within an IdentityServer implementation, which are not normally authorized with the local API authentication handler.\n- The use of DPoP to create sender-constrained tokens in IdentityServer that are consumed by external API resources.\n- The use of DPoP to sender-constrain refresh tokens issued to public clients.\n\n## Are you affected?\n\nThis vulnerability only affects IdentityServer implementations that are using the local APIs feature of IdentityServer and have explicitly enabled DPoP for local APIs. The local api authentication handler is configured with a call to either `AddLocalApi` or `AddLocalApiAuthentication`, and the opt-in to DPoP for local APIs is enabled via the `TokenMode` option. \n\nVulnerable implementations of IdentityServer would have configuration code similar to the following:\n\n```cs\nservices.AddAuthentication()\n .AddLocalApi(\"local\", options =\u003e \n {\n options.TokenMode = LocalApiTokenMode.DPoPAndBearer; // or LocalApiTokenMode.DPoPOnly\n });\n```\n\n### Patches\nThis vulnerability is patched in IdentityServer 7.0.8. Version 6.3 and below are unaffected, as they do not support DPoP in Local APIs.\n",
"id": "GHSA-v9xq-2mvm-x8xc",
"modified": "2024-10-28T21:49:51Z",
"published": "2024-10-28T19:44:10Z",
"references": [
{
"type": "WEB",
"url": "https://github.com/DuendeSoftware/IdentityServer/security/advisories/GHSA-v9xq-2mvm-x8xc"
},
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2024-49755"
},
{
"type": "WEB",
"url": "https://github.com/DuendeSoftware/IdentityServer/commit/f28cac921c1f545afe65af71a9327224755b6dac"
},
{
"type": "PACKAGE",
"url": "https://github.com/DuendeSoftware/IdentityServer"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:N/A:N",
"type": "CVSS_V3"
},
{
"score": "CVSS:4.0/AV:A/AC:L/AT:P/PR:N/UI:P/VC:L/VI:N/VA:N/SC:N/SI:N/SA:N",
"type": "CVSS_V4"
}
],
"summary": "Duende IdentityServer has insufficient validation of DPoP cnf claim in Local APIs "
}
Sightings
| Author | Source | Type | Date |
|---|
Nomenclature
- Seen: The vulnerability was mentioned, discussed, or observed by the user.
- Confirmed: The vulnerability has been validated from an analyst's perspective.
- Published Proof of Concept: A public proof of concept is available for this vulnerability.
- Exploited: The vulnerability was observed as exploited by the user who reported the sighting.
- Patched: The vulnerability was observed as successfully patched by the user who reported the sighting.
- Not exploited: The vulnerability was not observed as exploited by the user who reported the sighting.
- Not confirmed: The user expressed doubt about the validity of the vulnerability.
- Not patched: The vulnerability was not observed as successfully patched by the user who reported the sighting.