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