CVE-2024-49755: Duende.IdentityServer Duende IdentityServer Has Insufficient Validation Vulnerability

LOW
Advisory Identifier: GHSA-v9xq-2mvm-x8xc
CVSS 3.1
CWE-287
Published
Advisory Summary

CVE-2024-49755 is a LOW (CVSS 3.1) duende identityserver has insufficient validation vulnerability (CWE-287: Improper Authentication) affecting Duende.IdentityServer libraries in the NuGet ecosystem. The issue involves duende identityserver has insufficient validation of dpop cnf claim in local apis. Remediation is available by upgrading affected packages to version 7.0.8.

CVE-2024-49755 at a Glance

CVE Identifier CVE-2024-49755
GHSA Identifier GHSA-v9xq-2mvm-x8xc
Severity LOW
CVSS v3.1 Base Score 3.1
CWE Classification CWE-287: Improper Authentication
Affected Product Duende.IdentityServer
Package Ecosystem NuGet
Published Date
Last Updated

Security Impact

CVSS: 3.1

The security impact metrics below are parsed directly from the CVSS v3.1 vector string (CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:N/A:N).

Attack Vector Network (AV:N)
Attack Complexity High (AC:H)
Privileges Required None (PR:N)
User Interaction Required (UI:R)
Scope Unchanged (S:U)
Confidentiality Low (C:L)
Integrity None (I:N)
Availability None (A:N)

How to Fix CVE-2024-49755

To remediate this vulnerability, upgrade all affected Duende.IdentityServer dependencies to a patched release. Both direct and transitive dependencies should be checked, as frameworks or security libraries may pull in vulnerable versions transitively.

Duende.IdentityServer fixed: 7.0.8
Upgrade Duende.IdentityServer to 7.0.8
Verify Direct and Transitive Dependencies

Run the following command in your project directory to verify that all resolved dependencies use the patched release:

inspect dependencies for Duende.IdentityServer

How to Check if You Are Affected

To determine whether your application is affected by CVE-2024-49755, inspect your project dependencies for Duende.IdentityServer:

inspect dependencies for Duende.IdentityServer

Analyze the terminal output to locate any version of Duende.IdentityServer in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 7.0.8), your application is affected.

Note: Verify declared build manifests and deployed runtime container environments.

Technical Details

Vulnerability Mechanism & Technical Analysis

This vulnerability is classified under CWE-287: Improper Authentication, where when an actor claims to have a given identity, the product does not prove or insufficiently proves that the claim is correct. In Duende.IdentityServer, software state validation or input boundaries are circumvented during processing. Review the official source advisory statement below for specific affected components, classes, and reproduction details.

Source Advisory Statement

### Impact 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: ```cs 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.

CVE-2024-49755 Affected Duende.IdentityServer Versions

1 component(s)
Fixed Versions:
7.0.8
Product / Package Ecosystem Affected Versions Fixed Version
Duende.IdentityServer
NuGet
≥ 7.0.0
< 7.0.8
7.0.8

References

Frequently Asked Questions

What is CVE-2024-49755?
CVE-2024-49755 is a security vulnerability in Duende.IdentityServer involving Duende IdentityServer has insufficient validation of DPoP cnf claim in Local APIs under CWE-287: Improper Authentication.
Which Duende.IdentityServer versions are affected?
Affected versions include releases prior to 7.0.8 across affected packages: Duende.IdentityServer.
What version fixes CVE-2024-49755?
Upgrading to 7.0.8 (or the latest patched release for your respective branch) resolves the vulnerability.
Is Duende.IdentityServer affected?
Yes, Duende.IdentityServer is affected in releases prior to 7.0.8. Upgrade your dependency to 7.0.8 or later.
What is the CVSS score of CVE-2024-49755?
CVE-2024-49755 has a CVSS v3.1 base score of 3.1 (LOW) with vector string CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:N/A:N.
What CWE is associated with CVE-2024-49755?
CVE-2024-49755 is classified under CWE-287: Improper Authentication (When an actor claims to have a given identity, the product does not prove or insufficiently proves that the claim is correct.).
How can I check NuGet dependencies for CVE-2024-49755?
Run the dependency tree command: 'inspect dependencies for Duende.IdentityServer'. This command lists direct and transitive dependencies in your build configuration so you can verify if a vulnerable version is resolved.
Machine-readable OSV JSON OSV v1.5 Schema
Normalized schema output
{
  "schema_version" : "1.4.0",
  "id" : "GHSA-v9xq-2mvm-x8xc",
  "modified" : "2024-10-28T21:49:51Z",
  "published" : "2024-10-28T19:44:10Z",
  "aliases" : [ "CVE-2024-49755" ],
  "summary" : "Duende IdentityServer has insufficient validation of DPoP cnf claim in Local APIs ",
  "details" : "### Impact\nIdentityServer'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.\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 => \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",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:H/PR:N/UI:R/S:U/C:L/I:N/A:N"
  }, {
    "type" : "CVSS_V4",
    "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"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "NuGet",
      "name" : "Duende.IdentityServer"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "7.0.0"
      }, {
        "fixed" : "7.0.8"
      } ]
    } ]
  } ],
  "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"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-287" ],
    "severity" : "LOW",
    "github_reviewed" : true,
    "github_reviewed_at" : "2024-10-28T19:44:10Z",
    "nvd_published_at" : "2024-10-28T20:15:06Z"
  }
}