Staging Environment: Content and features may be unstable or change without notice.
Advisory details: github_osv / GHSA-g8ww-46x2-2p65
Advisory ID github_osv/GHSA-g8ww-46x2-2p65
Aliases CVE-2021-22902
Summary Denial of Service in Action Dispatch Impact ------ There is a possible Denial of Service vulnerability in Action Dispatch. Carefully crafted Accept headers can cause the mime type parser in Action Dispatch to do catastrophic backtracking in the regular expression engine. 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 Mime class Type MIME_REGEXP = /\A(?:\*\/\*|#{MIME_NAME}\/(?:\*|#{MIME_NAME})(?>\s*#{MIME_PARAMETER}\s*)*)\z/ end 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. * 6-0-Prevent-catastrophic-backtracking-during-mime-parsin.patch - Patch for 6.0 series * 6-1-Prevent-catastrophic-backtracking-during-mime-parsin.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 ------- Thanks to Security Curious <security...@pm.me> for reporting this!
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/2021/05/GHSA-g8ww-46x2-2p65/GHSA-g8ww-46x2-2p65.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.