Bug 1470706 (CVE-2017-11171)

Summary:	CVE-2017-11171 gnome-session: Bad reference counting in accept_ice_connection() permits resource exhaustion
Product:	[Other] Security Response	Reporter:	Pedro Sampaio <psampaio>
Component:	vulnerability	Assignee:	Red Hat Product Security <security-response-team>
Status:	CLOSED WONTFIX	QA Contact:
Severity:	low	Docs Contact:
Priority:	low
Version:	unspecified	CC:	jmccann, rstrode
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:		Doc Type:	If docs needed, set a value
Doc Text:	A denial-of-service flaw was found in the way gnome-session handled ICE connections. A local, authenticated attacker could potentially use this flaw to cause the gnome-session process to exhaust its file descriptors and enter an infinite loop, thereby leading to denial of service.	Story Points:	---
Clone Of:		Environment:
Last Closed:	2017-09-04 04:33:21 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:	1470707
Bug Blocks:	1470723

Description Pedro Sampaio 2017-07-13 13:48:18 UTC

Bad reference counting in the context of accept_ice_connection() in gsm-xsmp-server.c in old versions of gnome-session up until version 2.29.92 allows a local attacker to establish ICE connections to gnome-session with invalid authentication data (an invalid magic cookie). Each failed authentication attempt will leak a file descriptor in gnome-session. When the maximum number of file descriptors is exhausted in the gnome-session process, it will enter an infinite loop trying to communicate without success, consuming 100% of the CPU. The graphical session associated with the gnome-session process will stop working correctly, because communication with gnome-session is no longer possible.

Upstream patch:

https://github.com/GNOME/gnome-session/commit/b0dc999e0b45355314616321dbb6cb71e729fc9d

References:

https://bugzilla.suse.com/show_bug.cgi?id=1025068
https://bugzilla.suse.com/show_bug.cgi?id=1048274
http://seclists.org/oss-sec/2017/q3/121

Comment 1 Pedro Sampaio 2017-07-13 13:48:38 UTC

Created gnome-session tracking bugs for this issue:

Affects: fedora-all [bug 1470707]