Bug 1258802 (CVE-2015-6806)

Summary:	CVE-2015-6806 screen: Stack overflow due to deep recursion causing process freeze
Product:	[Other] Security Response	Reporter:	Adam Mariš <amaris>
Component:	vulnerability	Assignee:	Red Hat Product Security <security-response-team>
Status:	CLOSED WONTFIX	QA Contact:
Severity:	low	Docs Contact:
Priority:	low
Version:	unspecified	CC:	jrusnack, lnykryn, phracek
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	Bug Fix
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2015-11-05 04:04:12 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:	1258806
Bug Blocks:	1258805

Description Adam Mariš 2015-09-01 10:24:33 UTC

A vulnerability was found in screen causing stack overflow which results in crashing the screen server process. After running malicious command inside screen, it will recursively call MScrollV to depth n/256. This is time consuming and will overflow the stack if 'n' is huge.

CVE assignment:

http://seclists.org/oss-sec/2015/q3/485

Upstream patch:

http://git.savannah.gnu.org/cgit/screen.git/commit/?id=c336a32a1dcd445e6b83827f83531d4c6414e2cd

Upstream report (contains reproducer):

https://savannah.gnu.org/bugs/?45713

Comment 1 Adam Mariš 2015-09-01 10:28:27 UTC

Created screen tracking bugs for this issue:

Affects: fedora-all [bug 1258806]

Comment 3 Petr Hracek 2015-12-21 09:14:53 UTC

Shall I fix the screen bug or close it as WONTFIX too?

Why is this bug closed as WONTFIX?

Comment 4 Adam Mariš 2015-12-21 09:58:45 UTC

(In reply to Petr Hracek from comment #3)
> Shall I fix the screen bug or close it as WONTFIX too?
> 
> Why is this bug closed as WONTFIX?

This issue is not planned to be fixed in RHEL due to Low security impact.