Staging Environment: Content and features may be unstable or change without notice.
Advisory details: github_osv / GHSA-m63j-wh5w-c252
Advisory ID github_osv/GHSA-m63j-wh5w-c252
Aliases CVE-2019-5419
Summary # Denial 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: ``` ruby class UserController < ApplicationController def index render "index" end end ``` But the following code is not vulnerable: ```ruby class UserController < ApplicationController def index respond_to |format| format.html { render "index" } end end end ``` Implicit rendering is impacted, so this code is vulnerable: ```ruby class UserController < ApplicationController def index end end ``` But can be changed this this: ```ruby 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
Status Published
Exploitability 0.5
Weighted Severity 6.8
Risk 3.4
Affected and Fixed Packages Package Details
Introduced and Fixed Package Commit Patches Package Commit Patches Details
Weaknesses (0)
There are no known CWE.

No exploits are available.

No EPSS data available for this advisory.

Patch URL
There are no known patches.
Vector: CVSS:3.1/AV:N/AC:L/PR:N/UI:N/S:U/C:N/I:N/A:H Found at https://github.com/github/advisory-database/blob/main/advisories/github-reviewed/2019/03/GHSA-m63j-wh5w-c252/GHSA-m63j-wh5w-c252.json
Attack Vector (AV) Attack Complexity (AC) Privileges Required (PR) User Interaction (UI) Scope (S) Confidentiality Impact (C) Integrity Impact (I) Availability Impact (A)

network

adjacent_network

local

physical

low

high

none

low

high

none

required

unchanged

changed

high

low

none

high

low

none

high

low

none

There are no SSVC decisions available.