GHSA-M63J-WH5W-C252
Vulnerability from github – Published: 2019-03-13 17:25 – Updated: 2023-08-08 16:46Denial of Service Vulnerability in Action View
Impact
Specially crafted accept headers can cause the Action View template location code to consume 100% CPU, causing the server unable to process requests. This impacts all Rails applications that render views.
All users running an affected release should either upgrade or use one of the workarounds immediately.
Releases
The 6.0.0.beta3, 5.2.2.1, 5.1.6.2, 5.0.7.2, and 4.2.11.1 releases are available at the normal locations.
Workarounds
This vulnerability can be mitigated by wrapping render calls with respond_to blocks. For example, the following example is vulnerable:
class UserController < ApplicationController
def index
render "index"
end
end
But the following code is not vulnerable:
class UserController < ApplicationController
def index
respond_to |format|
format.html { render "index" }
end
end
end
Implicit rendering is impacted, so this code is vulnerable:
class UserController < ApplicationController
def index
end
end
But can be changed this this:
class UserController < ApplicationController
def index
respond_to |format|
format.html { render "index" }
end
end
end
Alternatively to specifying the format, the following monkey patch can be applied in an initializer:
$ cat config/initializers/formats_filter.rb
# frozen_string_literal: true
ActionDispatch::Request.prepend(Module.new do
def formats
super().select do |format|
format.symbol || format.ref == "*/*"
end
end
end)
Please note that only the 5.2.x, 5.1.x, 5.0.x, and 4.2.x 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.
Also note that the patches for this vulnerability are the same as CVE-2019-5418.
Credits
Thanks to John Hawthorn john@hawthorn.email of GitHub
{
"affected": [
{
"database_specific": {
"last_known_affected_version_range": "\u003c= 4.2.11.0"
},
"package": {
"ecosystem": "RubyGems",
"name": "actionview"
},
"ranges": [
{
"events": [
{
"introduced": "4.0.0"
},
{
"fixed": "4.2.11.1"
}
],
"type": "ECOSYSTEM"
}
]
},
{
"database_specific": {
"last_known_affected_version_range": "\u003c= 5.2.2.0"
},
"package": {
"ecosystem": "RubyGems",
"name": "actionview"
},
"ranges": [
{
"events": [
{
"introduced": "5.2.0"
},
{
"fixed": "5.2.2.1"
}
],
"type": "ECOSYSTEM"
}
]
},
{
"database_specific": {
"last_known_affected_version_range": "\u003c= 5.1.6.1"
},
"package": {
"ecosystem": "RubyGems",
"name": "actionview"
},
"ranges": [
{
"events": [
{
"introduced": "5.1.0"
},
{
"fixed": "5.1.6.2"
}
],
"type": "ECOSYSTEM"
}
]
},
{
"database_specific": {
"last_known_affected_version_range": "\u003c= 5.0.7.1"
},
"package": {
"ecosystem": "RubyGems",
"name": "actionview"
},
"ranges": [
{
"events": [
{
"introduced": "5.0.0"
},
{
"fixed": "5.0.7.2"
}
],
"type": "ECOSYSTEM"
}
]
},
{
"package": {
"ecosystem": "RubyGems",
"name": "actionview"
},
"ranges": [
{
"events": [
{
"introduced": "6.0.0.beta1"
},
{
"fixed": "6.0.0.beta3"
}
],
"type": "ECOSYSTEM"
}
]
}
],
"aliases": [
"CVE-2019-5419"
],
"database_specific": {
"cwe_ids": [
"CWE-400",
"CWE-770"
],
"github_reviewed": true,
"github_reviewed_at": "2020-06-16T21:45:03Z",
"nvd_published_at": "2019-03-27T14:29:01Z",
"severity": "HIGH"
},
"details": "# Denial of Service Vulnerability in Action View\n\nImpact \n------ \nSpecially crafted accept headers can cause the Action View template location code to consume 100% CPU, causing the server unable to process requests. This impacts all Rails applications that render views. \n\nAll users running an affected release should either upgrade or use one of the workarounds immediately. \n\nReleases \n-------- \nThe 6.0.0.beta3, 5.2.2.1, 5.1.6.2, 5.0.7.2, and 4.2.11.1 releases are available at the normal locations. \n\nWorkarounds \n----------- \nThis vulnerability can be mitigated by wrapping `render` calls with `respond_to` blocks. For example, the following example is vulnerable: \n\n``` ruby\nclass UserController \u003c ApplicationController \n def index \n render \"index\" \n end \nend \n``` \n\nBut the following code is not vulnerable: \n\n```ruby \nclass UserController \u003c ApplicationController \n def index \n respond_to |format| \n format.html { render \"index\" } \n end \n end \nend \n``` \n\nImplicit rendering is impacted, so this code is vulnerable: \n\n```ruby \nclass UserController \u003c ApplicationController \n def index \n end \nend \n``` \n\nBut can be changed this this: \n\n```ruby \nclass UserController \u003c ApplicationController \n def index \n respond_to |format| \n format.html { render \"index\" } \n end \n end \nend \n``` \n\nAlternatively to specifying the format, the following monkey patch can be applied in an initializer: \n\n``` \n$ cat config/initializers/formats_filter.rb \n# frozen_string_literal: true \n\nActionDispatch::Request.prepend(Module.new do \n def formats \n super().select do |format| \n format.symbol || format.ref == \"*/*\" \n end \n end \nend) \n``` \n\nPlease note that only the 5.2.x, 5.1.x, 5.0.x, and 4.2.x 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\nAlso note that the patches for this vulnerability are the same as CVE-2019-5418. \n\nCredits \n------- \nThanks to John Hawthorn \u003cjohn@hawthorn.email\u003e of GitHub ",
"id": "GHSA-m63j-wh5w-c252",
"modified": "2023-08-08T16:46:59Z",
"published": "2019-03-13T17:25:55Z",
"references": [
{
"type": "ADVISORY",
"url": "https://nvd.nist.gov/vuln/detail/CVE-2019-5419"
},
{
"type": "WEB",
"url": "https://github.com/rails/rails/pull/35708"
},
{
"type": "WEB",
"url": "https://github.com/rails/rails/commit/f4c70c2222180b8d9d924f00af0c7fd632e26715"
},
{
"type": "WEB",
"url": "https://access.redhat.com/errata/RHSA-2019:0796"
},
{
"type": "WEB",
"url": "https://access.redhat.com/errata/RHSA-2019:1147"
},
{
"type": "WEB",
"url": "https://access.redhat.com/errata/RHSA-2019:1149"
},
{
"type": "WEB",
"url": "https://access.redhat.com/errata/RHSA-2019:1289"
},
{
"type": "PACKAGE",
"url": "https://github.com/rails/rails"
},
{
"type": "WEB",
"url": "https://github.com/rubysec/ruby-advisory-db/blob/master/gems/actionview/CVE-2019-5419.yml"
},
{
"type": "WEB",
"url": "https://groups.google.com/forum/#!topic/rubyonrails-security/GN7w9fFAQeI"
},
{
"type": "WEB",
"url": "https://lists.debian.org/debian-lts-announce/2019/03/msg00042.html"
},
{
"type": "WEB",
"url": "https://lists.fedoraproject.org/archives/list/package-announce@lists.fedoraproject.org/message/Y43636TH4D6T46IC6N2RQVJTRFJAAYGA"
},
{
"type": "WEB",
"url": "https://weblog.rubyonrails.org/2019/3/13/Rails-4-2-5-1-5-1-6-2-have-been-released"
},
{
"type": "WEB",
"url": "http://lists.opensuse.org/opensuse-security-announce/2019-05/msg00011.html"
},
{
"type": "WEB",
"url": "http://lists.opensuse.org/opensuse-security-announce/2019-06/msg00025.html"
},
{
"type": "WEB",
"url": "http://lists.opensuse.org/opensuse-security-announce/2019-08/msg00001.html"
},
{
"type": "WEB",
"url": "http://www.openwall.com/lists/oss-security/2019/03/22/1"
}
],
"schema_version": "1.4.0",
"severity": [
{
"score": "CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H",
"type": "CVSS_V3"
}
],
"summary": "Denial of Service Vulnerability in Action View"
}
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.