Bug 1854328 (CVE-2020-5238)

Summary:	CVE-2020-5238 cmark-gfm: Exponential time to parse certain inputs could lead to DoS
Product:	[Other] Security Response	Reporter:	Marian Rehak <mrehak>
Component:	vulnerability	Assignee:	Red Hat Product Security <security-response-team>
Status:	CLOSED ERRATA	QA Contact:
Severity:	medium	Docs Contact:
Priority:	medium
Version:	unspecified	CC:	petersen
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:	ghc-cmark-gfm 0.29.0.gfm.1	Doc Type:	If docs needed, set a value
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2021-05-18 20:34:00 UTC	Type:	---
Regression:	---	Mount Type:	---
Documentation:	---	CRM:
Verified Versions:		Category:	---
oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---	Target Upstream Version:
Embargoed:
Bug Depends On:	1854329, 1855805, 1865911
Bug Blocks:	1854330

Description Marian Rehak 2020-07-07 08:08:18 UTC

The table extension in GitHub Flavored Markdown before version 0.29.0.gfm.1 takes O(n * n) time to parse certain inputs. An attacker could craft a markdown table which would take an unreasonably long time to process, causing a denial of service. This issue does not affect the upstream cmark project.

Upstream Advisory:

https://github.com/github/cmark-gfm/security/advisories/GHSA-7gc6-9qr5-hc85

Comment 1 Marian Rehak 2020-07-07 08:09:03 UTC

Created ghc-cmark-gfm tracking bugs for this issue:

Affects: fedora-all [bug 1854329]

Comment 2 Stefan Cornelius 2020-07-10 14:14:04 UTC

Patch:
https://github.com/github/cmark-gfm/commit/85d895289c5ab67f988ca659493a64abb5fec7b4

Comment 6 errata-xmlrpc 2021-05-18 16:32:28 UTC

This issue has been addressed in the following products:

  Red Hat Enterprise Linux 8

Via RHSA-2021:1972 https://access.redhat.com/errata/RHSA-2021:1972

Comment 7 Product Security DevOps Team 2021-05-18 20:34:00 UTC

This bug is now closed. Further updates for individual products will be reflected on the CVE page(s):

https://access.redhat.com/security/cve/cve-2020-5238