CVE-2021-22904: Actionpack Denial of Service Vulnerability

HIGH
Advisory Identifier: GHSA-7wjx-3g7j-8584
CVSS 7.5
CWE-400
Published
Advisory Summary

CVE-2021-22904 is a HIGH (CVSS 7.5) denial of service vulnerability (CWE-400: Uncontrolled Resource Consumption) affecting Actionpack libraries in the RubyGems ecosystem. The issue involves possible dos vulnerability in action controller token authentication. Remediation is available by upgrading affected packages to version 6.0.3.7, 6.1.3.2, 5.2.6, 5.2.4.6.

CVE-2021-22904 at a Glance

CVE Identifier CVE-2021-22904
GHSA Identifier GHSA-7wjx-3g7j-8584
Severity HIGH
CVSS v3.1 Base Score 7.5
CWE Classification CWE-400: Uncontrolled Resource Consumption
Affected Product Actionpack
Package Ecosystem RubyGems
Published Date
Last Updated

Security Impact

CVSS: 7.5

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

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

How to Fix CVE-2021-22904

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

actionpack fixed: 6.0.3.7
Upgrade actionpack to 6.0.3.7
actionpack fixed: 6.1.3.2
Upgrade actionpack to 6.1.3.2
actionpack fixed: 5.2.6
Upgrade actionpack to 5.2.6
actionpack fixed: 5.2.4.6
Upgrade actionpack to 5.2.4.6
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 actionpack

How to Check if You Are Affected

To determine whether your application is affected by CVE-2021-22904, inspect your project dependencies for Actionpack:

inspect dependencies for actionpack

Analyze the terminal output to locate any version of Actionpack in your dependency tree. If any resolved version matches the vulnerable ranges listed in the table below (for example, versions earlier than 6.0.3.7), 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-400: Uncontrolled Resource Consumption, where the product does not properly control the allocation and maintenance of a limited resource. In Actionpack, 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

There is a possible DoS vulnerability in the Token Authentication logic in Action Controller. Versions Affected: >= 4.0.0 Not affected: < 4.0.0 Fixed Versions: 6.1.3.2, 6.0.3.7, 5.2.4.6, 5.2.6 Impact ------ Impacted code uses `authenticate_or_request_with_http_token` or `authenticate_with_http_token` for request authentication. Impacted code will look something like this: ``` class PostsController < ApplicationController before_action :authenticate private def authenticate authenticate_or_request_with_http_token do |token, options| # ... end end end ``` All users running an affected release should either upgrade or use one of the workarounds immediately. Releases -------- The fixed releases are available at the normal locations. Workarounds ----------- The following monkey patch placed in an initializer can be used to work around the issue: ```ruby module ActionController::HttpAuthentication::Token AUTHN_PAIR_DELIMITERS = /(?:,|;|\t)/ end ``` Patches ------- To aid users who aren't able to upgrade immediately we have provided patches for the two supported release series. They are in git-am format and consist of a single changeset. * 5-2-http-authentication-dos.patch - Patch for 5.2 series * 6-0-http-authentication-dos.patch - Patch for 6.0 series * 6-1-http-authentication-dos.patch - Patch for 6.1 series Please note that only the 6.1.Z, 6.0.Z, and 5.2.Z series are supported at present. Users of earlier unsupported releases are advised to upgrade as soon as possible as we cannot guarantee the continued availability of security fixes for unsupported releases. Credits ------- Thank you to https://hackerone.com/wonda_tea_coffee for reporting this issue!

CVE-2021-22904 Affected Actionpack Versions

4 component(s)
Fixed Versions:
6.0.3.76.1.3.25.2.65.2.4.6
Product / Package Ecosystem Affected Versions Fixed Version
actionpack
RubyGems
≥ 6.0.0
< 6.0.3.7
6.0.3.7
actionpack
RubyGems
≥ 6.1.0
< 6.1.3.2
6.1.3.2
actionpack
RubyGems
≥ 5.2.5
< 5.2.6
5.2.6
actionpack
RubyGems
≥ 4.0.0
< 5.2.4.6
5.2.4.6

References

Frequently Asked Questions

What is CVE-2021-22904?
CVE-2021-22904 is a security vulnerability in Actionpack involving Possible DoS Vulnerability in Action Controller Token Authentication under CWE-400: Uncontrolled Resource Consumption.
Which Actionpack versions are affected?
Affected versions include releases prior to 6.0.3.7, 6.1.3.2, 5.2.6, 5.2.4.6 across affected packages: actionpack.
What version fixes CVE-2021-22904?
Upgrading to 6.0.3.7, 6.1.3.2, 5.2.6, 5.2.4.6 (or the latest patched release for your respective branch) resolves the vulnerability.
Is actionpack affected?
Yes, actionpack is affected in releases prior to 6.0.3.7, 6.1.3.2, 5.2.6, 5.2.4.6. Upgrade your dependency to 6.0.3.7, 6.1.3.2, 5.2.6, 5.2.4.6 or later.
What is the CVSS score of CVE-2021-22904?
CVE-2021-22904 has a CVSS v3.1 base score of 7.5 (HIGH) with vector string CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H.
What CWE is associated with CVE-2021-22904?
CVE-2021-22904 is classified under CWE-400: Uncontrolled Resource Consumption (The product does not properly control the allocation and maintenance of a limited resource.).
How can I check RubyGems dependencies for CVE-2021-22904?
Run the dependency tree command: 'inspect dependencies for actionpack'. 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-7wjx-3g7j-8584",
  "modified" : "2023-08-08T16:06:25Z",
  "published" : "2021-05-05T19:49:12Z",
  "aliases" : [ "CVE-2021-22904" ],
  "summary" : "Possible DoS Vulnerability in Action Controller Token Authentication",
  "details" : "There is a possible DoS vulnerability in the Token Authentication logic in Action Controller.\n\nVersions Affected:  >= 4.0.0\nNot affected:       < 4.0.0\nFixed Versions:     6.1.3.2, 6.0.3.7, 5.2.4.6, 5.2.6\n\nImpact\n------\nImpacted code uses `authenticate_or_request_with_http_token` or `authenticate_with_http_token` for request authentication.  Impacted code will look something like this:\n\n```\nclass PostsController < ApplicationController\n  before_action :authenticate\n\n  private\n\n  def authenticate\n    authenticate_or_request_with_http_token do |token, options|\n      # ...\n    end\n  end\nend\n```\n\nAll users running an affected release should either upgrade or use one of the workarounds immediately.\n\nReleases\n--------\nThe fixed releases are available at the normal locations.\n\nWorkarounds\n-----------\nThe following monkey patch placed in an initializer can be used to work around the issue:\n\n```ruby\nmodule ActionController::HttpAuthentication::Token\n  AUTHN_PAIR_DELIMITERS = /(?:,|;|\\t)/\nend\n```\n\nPatches\n-------\nTo aid users who aren't able to upgrade immediately we have provided patches for the two supported release series. They are in git-am format and consist of a single changeset.\n\n* 5-2-http-authentication-dos.patch - Patch for 5.2 series\n* 6-0-http-authentication-dos.patch - Patch for 6.0 series\n* 6-1-http-authentication-dos.patch - Patch for 6.1 series\n\nPlease note that only the 6.1.Z, 6.0.Z, and 5.2.Z series are supported at present. Users of earlier unsupported releases are advised to upgrade as soon as possible as we cannot guarantee the continued availability of security fixes for unsupported releases.\n\nCredits\n-------\nThank you to https://hackerone.com/wonda_tea_coffee for reporting this issue!",
  "severity" : [ {
    "type" : "CVSS_V3",
    "score" : "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H"
  } ],
  "affected" : [ {
    "package" : {
      "ecosystem" : "RubyGems",
      "name" : "actionpack"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "6.0.0"
      }, {
        "fixed" : "6.0.3.7"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 6.0.3.6"
    }
  }, {
    "package" : {
      "ecosystem" : "RubyGems",
      "name" : "actionpack"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "6.1.0"
      }, {
        "fixed" : "6.1.3.2"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 6.1.3.1"
    }
  }, {
    "package" : {
      "ecosystem" : "RubyGems",
      "name" : "actionpack"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "5.2.5"
      }, {
        "fixed" : "5.2.6"
      } ]
    } ]
  }, {
    "package" : {
      "ecosystem" : "RubyGems",
      "name" : "actionpack"
    },
    "ranges" : [ {
      "type" : "ECOSYSTEM",
      "events" : [ {
        "introduced" : "4.0.0"
      }, {
        "fixed" : "5.2.4.6"
      } ]
    } ],
    "database_specific" : {
      "last_known_affected_version_range" : "<= 5.2.4.5"
    }
  } ],
  "references" : [ {
    "type" : "ADVISORY",
    "url" : "https://nvd.nist.gov/vuln/detail/CVE-2021-22904"
  }, {
    "type" : "WEB",
    "url" : "https://hackerone.com/reports/1101125"
  }, {
    "type" : "WEB",
    "url" : "https://discuss.rubyonrails.org/t/cve-2021-22904-possible-dos-vulnerability-in-action-controller-token-authentication/77869"
  }, {
    "type" : "PACKAGE",
    "url" : "https://github.com/rails/rails"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/rails/rails/releases/tag/v5.2.4.6"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/rails/rails/releases/tag/v5.2.6"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/rails/rails/releases/tag/v6.0.3.7"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/rails/rails/releases/tag/v6.1.3.2"
  }, {
    "type" : "WEB",
    "url" : "https://github.com/rubysec/ruby-advisory-db/blob/master/gems/actionpack/CVE-2021-22904.yml"
  }, {
    "type" : "WEB",
    "url" : "https://groups.google.com/g/rubyonrails-security/c/Pf1TjkOBdyQ"
  }, {
    "type" : "WEB",
    "url" : "https://security.netapp.com/advisory/ntap-20210805-0009"
  } ],
  "database_specific" : {
    "cwe_ids" : [ "CWE-400" ],
    "severity" : "HIGH",
    "github_reviewed" : true,
    "github_reviewed_at" : "2021-05-05T19:48:31Z",
    "nvd_published_at" : "2021-06-11T16:15:00Z"
  }
}