Bug 1667864 (CVE-2019-6293)

Summary:	CVE-2019-6293 flex: Recursive calls in the function mark_beginning_as_normal resulting in a denial of service
Product:	[Other] Security Response	Reporter:	Dhananjay Arunesh <darunesh>
Component:	vulnerability	Assignee:	Red Hat Product Security <security-response-team>
Status:	CLOSED ERRATA	QA Contact:
Severity:	low	Docs Contact:
Priority:	low
Version:	unspecified	CC:	codonell
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	If docs needed, set a value
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2021-10-27 03:24:14 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:	1667865, 1716237, 1716238
Bug Blocks:	1667868

Description Dhananjay Arunesh 2019-01-21 10:17:32 UTC

An issue was discovered in the function mark_beginning_as_normal in nfa.c in flex 2.6.4. There is a stack exhaustion problem caused by the mark_beginning_as_normal function making recursive calls to itself in certain scenarios involving lots of '*' characters. Remote attackers could leverage this vulnerability to cause a denial-of-service.


Upstream Issue:

https://github.com/westes/flex/issues/414

Comment 1 Dhananjay Arunesh 2019-01-21 10:17:39 UTC

Created flex tracking bugs for this issue:

Affects: fedora-all [bug 1667865]

Comment 3 Stefan Cornelius 2019-06-02 22:52:24 UTC

Statement:

This issue affects the versions of flex as shipped with Red Hat Enterprise Linux 5, 6, 7, and 8.

Red Hat Enterprise Linux 5 is now in Extended Life Phase of the support and maintenance life cycle. This issue is not currently planned to be addressed in future updates. For additional information, refer to the Red Hat Enterprise Linux Life Cycle: https://access.redhat.com/support/policy/updates/errata/.

Red Hat Enterprise Linux 6 is now in Maintenance Support 2 Phase of the support and maintenance life cycle. This has been rated as having a security impact of Low, and is not currently planned to be addressed in future updates. For additional information, refer to the Red Hat Enterprise Linux Life Cycle: https://access.redhat.com/support/policy/updates/errata/.