Open Redirect in ActionPack

Overview

There is a possible open redirect vulnerability in the Host Authorization middleware in Action Pack. This vulnerability has been assigned the CVE identifier CVE-2021-22942.

Versions Affected: >= 6.0.0. Not affected: < 6.0.0 Fixed Versions: 6.1.4.1, 6.0.4.1

Impact

Specially crafted “X-Forwarded-Host” headers in combination with certain “allowed host” formats can cause the Host Authorization middleware in Action Pack to redirect users to a malicious website.

Impacted applications will have allowed hosts with a leading dot. For example, configuration files that look like this:

config.hosts <<  '.EXAMPLE.com'

When an allowed host contains a leading dot, a specially crafted Host header can be used to redirect to a malicious website.

This vulnerability is similar to CVE-2021-22881, but CVE-2021-22881 did not take in to account domain name case sensitivity.

Releases

The fixed releases are available at the normal locations.

Workarounds

In the case a patch can’t be applied, the following monkey patch can be used in an initializer:

module ActionDispatch
  class HostAuthorization
    HOSTNAME = /[a-z0-9.-]+|\[[a-f0-9]*:[a-f0-9.:]+\]/i
    VALID_ORIGIN_HOST = /\A(#{HOSTNAME})(?::\d+)?\z/
    VALID_FORWARDED_HOST = /(?:\A|,[ ]?)(#{HOSTNAME})(?::\d+)?\z/

    private
      def authorized?(request)
        origin_host =
          request.get_header("HTTP_HOST")&.slice(VALID_ORIGIN_HOST, 1) || ""
        forwarded_host =
          request.x_forwarded_host&.slice(VALID_FORWARDED_HOST, 1) || ""
        @permissions.allows?(origin_host) &&
          (forwarded_host.blank? || @permissions.allows?(forwarded_host))
      end
  end
end

Actionpack has possible cross-site scripting vulnerability via User Supplied Values to redirect_to

The redirect_to method in Rails allows provided values to contain characters which are not legal in an HTTP header value. This results in the potential for downstream services which enforce RFC compliance on HTTP response headers to remove the assigned Location header. This vulnerability has been assigned the CVE identifier CVE-2023-28362.

Versions Affected: All. Not affected: None Fixed Versions: 7.0.5.1, 6.1.7.4

Impact

This introduces the potential for a Cross-site-scripting (XSS) payload to be delivered on the now static redirection page. Note that this both requires user interaction and for a Rails app to be configured to allow redirects to external hosts (defaults to false in Rails >= 7.0.x).

Releases

The FIXED releases are available at the normal locations.

Workarounds

Avoid providing user supplied URLs with arbitrary schemes to the redirect_to method.

ReDoS based DoS vulnerability in Action Dispatch

There is a possible regular expression based DoS vulnerability in Action Dispatch related to the If-None-Match header. This vulnerability has been assigned the CVE identifier CVE-2023-22795.

Versions Affected: All Not affected: None Fixed Versions: 5.2.8.15 (Rails LTS), 6.1.7.1, 7.0.4.1

Impact

A specially crafted HTTP If-None-Match header can cause the regular expression engine to enter a state of catastrophic backtracking, when on a version of Ruby below 3.2.0. This can cause the process to use large amounts of CPU and memory, leading to a possible DoS vulnerability 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

We recommend that all users upgrade to one of the FIXED versions. In the meantime, users can mitigate this vulnerability by using a load balancer or other device to filter out malicious If-None-Match headers before they reach the application.

Users on Ruby 3.2.0 or greater are not affected by this vulnerability. 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.

6-1-Avoid-regex-backtracking-on-If-None-Match-header.patch - Patch for 6.1 series
7-0-Avoid-regex-backtracking-on-If-None-Match-header.patch - Patch for 7.0 series

Please note that only the 7.0.Z and 6.1.Z series are supported at present, and 6.0.Z for severe vulnerabilities. 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.

Cross-site Scripting in actionpack

actionpack from the Ruby on Rails project is vulnerable to Cross-site Scripting in the Route Error Page. This issue has been patched with this commit.

This vulnerability is disputed by the Rails security team. It requires that the developer is tricked into copy pasting a malicious javascript-containing string into a development-only error page accessible only via localhost.

Cross-site Scripting Vulnerability in Action Pack

There is a possible XSS vulnerability in Rails / Action Pack. This vulnerability has been assigned the CVE identifier CVE-2022-22577.

Versions Affected: >= 5.2.0 Not affected: < 5.2.0 Fixed Versions: 7.0.2.4, 6.1.5.1, 6.0.4.8, 5.2.7.1

Impact

CSP headers were only sent along with responses that Rails considered as HTML responses. This left API requests without CSP headers, which could possibly expose users to XSS attacks.

Releases

The FIXED releases are available at the normal locations.

Workarounds

Set a CSP for your API responses manually.

ReDoS based DoS vulnerability in Action Dispatch

There is a possible regular expression based DoS vulnerability in Action Dispatch. This vulnerability has been assigned the CVE identifier CVE-2023-22792.

Versions Affected: >= 3.0.0 Not affected: < 3.0.0 Fixed Versions: 5.2.8.15 (Rails LTS), 6.1.7.1, 7.0.4.1 Impact

Specially crafted cookies, in combination with a specially crafted XFORWARDEDHOST header can cause the regular expression engine to enter a state of catastrophic backtracking. This can cause the process to use large amounts of CPU and memory, leading to a possible DoS vulnerability 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

We recommend that all users upgrade to one of the FIXED versions. In the meantime, users can mitigate this vulnerability by using a load balancer or other device to filter out malicious XFORWARDEDHOST headers before they reach the application. 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.

6-1-Use-string-split-instead-of-regex-for-domain-parts.patch - Patch for 6.1 series
7-0-Use-string-split-instead-of-regex-for-domain-parts.patch - Patch for 7.0 series

Please note that only the 7.0.Z and 6.1.Z series are supported at present, and 6.0.Z for severe vulnerabilities. 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.

https://rubyonrails.org/2023/1/17/Rails-Versions-6-0-6-1-6-1-7-1-7-0-4-1-have-been-released

actionpack Open Redirect in Host Authorization Middleware

Specially crafted X-Forwarded-Host headers in combination with certain allowed host formats can cause the Host Authorization middleware in Action Pack to redirect users to a malicious website.

Impacted applications will have allowed hosts with a leading dot. For example, configuration files that look like this:

config.hosts <<  '.EXAMPLE.com'

When an allowed host contains a leading dot, a specially crafted Host header can be used to redirect to a malicious website.

This vulnerability is similar to CVE-2021-22881 and CVE-2021-22942.

Releases

The fixed releases are available at the normal locations.

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.

• 6-0-host-authorzation-open-redirect.patch - Patch for 6.0 series
• 6-1-host-authorzation-open-redirect.patch - Patch for 6.1 series
• 7-0-host-authorzation-open-redirect.patch - Patch for 7.0 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.

Possible ReDoS vulnerability in HTTP Token authentication in Action Controller

There is a possible ReDoS vulnerability in Action Controller's HTTP Token authentication. This vulnerability has been assigned the CVE identifier CVE-2024-47887.

Impact

For applications using HTTP Token authentication via authenticate_or_request_with_http_token or similar, a carefully crafted header may cause header parsing to take an unexpected amount of time, possibly resulting in a DoS vulnerability. All users running an affected release should either upgrade or apply the relevant patch immediately.

Ruby 3.2 has mitigations for this problem, so Rails applications using Ruby 3.2 or newer are unaffected. Rails 8.0.0.beta1 depends on Ruby 3.2 or greater so is unaffected.

Releases

The fixed releases are available at the normal locations.

Workarounds

Users on Ruby 3.2 are unaffected by this issue.

Credits

Thanks to scyoon for reporting

Possible Content Security Policy bypass in Action Dispatch

There is a possible Cross Site Scripting (XSS) vulnerability in the content_security_policy helper in Action Pack.

Impact

Applications which set Content-Security-Policy (CSP) headers dynamically from untrusted user input may be vulnerable to carefully crafted inputs being able to inject new directives into the CSP. This could lead to a bypass of the CSP and its protection against XSS and other attacks.

Releases

The fixed releases are available at the normal locations.

Workarounds

Applications can avoid setting CSP headers dynamically from untrusted input, or can validate/sanitize that input.

Credits

Thanks to ryotak for the report!

Exposure of information in Action Pack

Impact

Under certain circumstances response bodies will not be closed, for example a bug in a webserver or a bug in a Rack middleware. In the event a response is not notified of a close, ActionDispatch::Executor will not know to reset thread local state for the next request. This can lead to data being leaked to subsequent requests, especially when interacting with ActiveSupport::CurrentAttributes.

Upgrading to the FIXED versions of Rails will ensure mitigation of this issue even in the context of a buggy webserver or middleware implementation.

Patches

This has been fixed in Rails 7.0.2.2, 6.1.4.6, 6.0.4.6, and 5.2.6.2.

Workarounds

Upgrading is highly recommended, but to work around this problem the following middleware can be used:

class GuardedExecutor < ActionDispatch::Executor
  def call(env)
    ensure_completed!
    super
  end

  private

    def ensure_completed!
      @executor.new.complete! if @executor.active?
    end
end

# Ensure the guard is inserted before ActionDispatch::Executor
Rails.application.configure do
  config.middleware.swap ActionDispatch::Executor, GuardedExecutor, executor
end

Possible ReDoS vulnerability in query parameter filtering in Action Dispatch

There is a possible ReDoS vulnerability in the query parameter filtering routines of Action Dispatch. This vulnerability has been assigned the CVE identifier CVE-2024-41128.

Impact

Carefully crafted query parameters can cause query parameter filtering to take an unexpected amount of time, possibly resulting in a DoS vulnerability. All users running an affected release should either upgrade or apply the relevant patch immediately.

Ruby 3.2 has mitigations for this problem, so Rails applications using Ruby 3.2 or newer are unaffected. Rails 8.0.0.beta1 depends on Ruby 3.2 or greater so is unaffected.

Releases

The fixed releases are available at the normal locations.

Workarounds

Users on Ruby 3.2 are unaffected by this issue.

Credits

Thanks to scyoon for the report and patches!

Possible Open Redirect in Host Authorization Middleware

There is a possible open redirect vulnerability in the Host Authorization middleware in Action Pack. This vulnerability has been assigned the CVE identifier CVE-2021-22942.

Versions Affected: >= 6.0.0. Not affected: < 6.0.0 Fixed Versions: 6.1.4.1, 6.0.4.1

Impact

Specially crafted “X-Forwarded-Host” headers in combination with certain “allowed host” formats can cause the Host Authorization middleware in Action Pack to redirect users to a malicious website.

Impacted applications will have allowed hosts with a leading dot. For example, configuration files that look like this:

config.hosts <<  '.EXAMPLE.com'

When an allowed host contains a leading dot, a specially crafted Host header can be used to redirect to a malicious website.

This vulnerability is similar to CVE-2021-22881, but CVE-2021-22881 did not take in to account domain name case sensitivity.

Releases

The fixed releases are available at the normal locations.

Workarounds

In the case a patch can’t be applied, the following monkey patch can be used in an initializer:

module ActionDispatch
  class HostAuthorization
    HOSTNAME = /[a-z0-9.-]+|\[[a-f0-9]*:[a-f0-9.:]+\]/i
    VALID_ORIGIN_HOST = /\A(#{HOSTNAME})(?::\d+)?\z/
    VALID_FORWARDED_HOST = /(?:\A|,[ ]?)(#{HOSTNAME})(?::\d+)?\z/

    private
      def authorized?(request)
        origin_host =
          request.get_header("HTTP_HOST")&.slice(VALID_ORIGIN_HOST, 1) || ""
        forwarded_host =
          request.x_forwarded_host&.slice(VALID_FORWARDED_HOST, 1) || ""
        @permissions.allows?(origin_host) &&
          (forwarded_host.blank? || @permissions.allows?(forwarded_host))
      end
  end
end

Possible Open Redirect in Host Authorization Middleware

There is a possible open redirect vulnerability in the Host Authorization middleware in Action Pack.

Specially crafted X-Forwarded-Host headers in combination with certain allowed host formats can cause the Host Authorization middleware in Action Pack to redirect users to a malicious website.

Impacted applications will have allowed hosts with a leading dot. For example, configuration files that look like this:

config.hosts <<  '.EXAMPLE.com'

When an allowed host contains a leading dot, a specially crafted Host header can be used to redirect to a malicious website.

This vulnerability is similar to CVE-2021-22881 and CVE-2021-22942.

Releases

The fixed releases are available at the normal locations.

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.

• 6-0-host-authorzation-open-redirect.patch - Patch for 6.0 series
• 6-1-host-authorzation-open-redirect.patch - Patch for 6.1 series
• 7-0-host-authorzation-open-redirect.patch - Patch for 7.0 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.

Possible XSS Vulnerability in Action Pack

There is a possible XSS vulnerability in Rails / Action Pack. This vulnerability has been assigned the CVE identifier CVE-2022-22577.

Versions Affected: >= 5.2.0 Not affected: < 5.2.0 Fixed Versions: 7.0.2.4, 6.1.5.1, 6.0.4.8, 5.2.7.1

Impact

CSP headers were only sent along with responses that Rails considered as HTML responses. This left API requests without CSP headers, which could possibly expose users to XSS attacks.

Releases

The FIXED releases are available at the normal locations.

Workarounds

Set a CSP for your API responses manually.

Possible exposure of information vulnerability in Action Pack

Impact

Under certain circumstances response bodies will not be closed, for example a bug in a webserver (https://github.com/puma/puma/pull/2812) or a bug in a Rack middleware. In the event a response is not notified of a close, ActionDispatch::Executor will not know to reset thread local state for the next request. This can lead to data being leaked to subsequent requests, especially when interacting with ActiveSupport::CurrentAttributes.

Upgrading to the FIXED versions of Rails will ensure mitigation if this issue even in the context of a buggy webserver or middleware implementation.

Patches

This has been fixed in Rails 7.0.2.2, 6.1.4.6, 6.0.4.6, and 5.2.6.2.

Workarounds

Upgrading is highly recommended, but to work around this problem the following middleware can be used:

class GuardedExecutor < ActionDispatch::Executor
  def call(env)
    ensure_completed!
    super
  end

  private

    def ensure_completed!
      @executor.new.complete! if @executor.active?
    end
end

# Ensure the guard is inserted before ActionDispatch::Executor
Rails.application.configure do
  config.middleware.swap ActionDispatch::Executor, GuardedExecutor, executor
end

ReDoS based DoS vulnerability in Action Dispatch

There is a possible regular expression based DoS vulnerability in Action Dispatch. This vulnerability has been assigned the CVE identifier CVE-2023-22792.

Versions Affected: >= 3.0.0 Not affected: < 3.0.0 Fixed Versions: 6.1.7.1, 7.0.4.1

Impact

Specially crafted cookies, in combination with a specially crafted XFORWARDEDHOST header can cause the regular expression engine to enter a state of catastrophic backtracking. This can cause the process to use large amounts of CPU and memory, leading to a possible DoS vulnerability All users running an affected release should either upgrade or use one of the workarounds immediately.

Workarounds

We recommend that all users upgrade to one of the FIXED versions. In the meantime, users can mitigate this vulnerability by using a load balancer or other device to filter out malicious XFORWARDEDHOST headers before they reach the application.

ReDoS based DoS vulnerability in Action Dispatch

There is a possible regular expression based DoS vulnerability in Action Dispatch related to the If-None-Match header. This vulnerability has been assigned the CVE identifier CVE-2023-22795.

Versions Affected: All Not affected: None Fixed Versions: 6.1.7.1, 7.0.4.1

Impact

A specially crafted HTTP If-None-Match header can cause the regular expression engine to enter a state of catastrophic backtracking, when on a version of Ruby below 3.2.0. This can cause the process to use large amounts of CPU and memory, leading to a possible DoS vulnerability All users running an affected release should either upgrade or use one of the workarounds immediately.

Workarounds

We recommend that all users upgrade to one of the FIXED versions. In the meantime, users can mitigate this vulnerability by using a load balancer or other device to filter out malicious If-None-Match headers before they reach the application.

Users on Ruby 3.2.0 or greater are not affected by this vulnerability.

Possible XSS via User Supplied Values to redirect_to

The redirect_to method in Rails allows provided values to contain characters which are not legal in an HTTP header value. This results in the potential for downstream services which enforce RFC compliance on HTTP response headers to remove the assigned Location header. This vulnerability has been assigned the CVE identifier CVE-2023-28362.

Versions Affected: All. Not affected: None Fixed Versions: 7.0.5.1, 6.1.7.4

Impact

This introduces the potential for a Cross-site-scripting (XSS) payload to be delivered on the now static redirection page. Note that this both requires user interaction and for a Rails app to be configured to allow redirects to external hosts (defaults to false in Rails >= 7.0.x).

Releases

The FIXED releases are available at the normal locations.

Workarounds

Avoid providing user supplied URLs with arbitrary schemes to the redirect_to method.

Possible ReDoS vulnerability in query parameter filtering in Action Dispatch

There is a possible ReDoS vulnerability in the query parameter filtering routines of Action Dispatch. This vulnerability has been assigned the CVE identifier CVE-2024-41128.

Impact

Carefully crafted query parameters can cause query parameter filtering to take an unexpected amount of time, possibly resulting in a DoS vulnerability. All users running an affected release should either upgrade or apply the relevant patch immediately.

Ruby 3.2 has mitigations for this problem, so Rails applications using Ruby 3.2 or newer are unaffected. Rails 8.0.0.beta1 depends on Ruby 3.2 or greater so is unaffected.

Releases

The fixed releases are available at the normal locations.

Workarounds

Users on Ruby 3.2 are unaffected by this issue.

Credits

Thanks to scyoon for the report and patches!

Possible ReDoS vulnerability in HTTP Token authentication in Action Controller

There is a possible ReDoS vulnerability in Action Controller's HTTP Token authentication. This vulnerability has been assigned the CVE identifier CVE-2024-47887.

Impact

For applications using HTTP Token authentication via authenticate_or_request_with_http_token or similar, a carefully crafted header may cause header parsing to take an unexpected amount of time, possibly resulting in a DoS vulnerability. All users running an affected release should either upgrade or apply the relevant patch immediately.

Ruby 3.2 has mitigations for this problem, so Rails applications using Ruby 3.2 or newer are unaffected. Rails 8.0.0.beta1 depends on Ruby 3.2 or greater so is unaffected.

Releases

The fixed releases are available at the normal locations.

Workarounds

Users on Ruby 3.2 are unaffected by this issue.

Credits

Thanks to scyoon for reporting

Possible Content Security Policy bypass in Action Dispatch

There is a possible Cross Site Scripting (XSS) vulnerability in the content_security_policy helper in Action Pack.

Impact

Applications which set Content-Security-Policy (CSP) headers dynamically from untrusted user input may be vulnerable to carefully crafted inputs being able to inject new directives into the CSP. This could lead to a bypass of the CSP and its protection against XSS and other attacks.

Releases

The fixed releases are available at the normal locations.

Workarounds

Applications can avoid setting CSP headers dynamically from untrusted input, or can validate/sanitize that input.

Credits

Thanks to ryotak for the report!