Bug 1274258 (CVE-2015-7850)

Summary:	CVE-2015-7850 ntp: remote configuration denial of service vulnerability
Product:	[Other] Security Response	Reporter:	Martin Prpič <mprpic>
Component:	vulnerability	Assignee:	Red Hat Product Security <security-response-team>
Status:	CLOSED NOTABUG	QA Contact:
Severity:	low	Docs Contact:
Priority:	low
Version:	unspecified	CC:	dsirrine, jaeshin, mlichvar, moshiro, sardella, slawomir, yozone
Target Milestone:	---	Keywords:	Security
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:	ntp 4.2.8p4	Doc Type:	Bug Fix
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2016-01-07 12:07:18 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:	1296167
Bug Blocks:	1260670

Description Martin Prpič 2015-10-22 11:30:26 UTC

The following flaw was found in ntpd:

An exploitable denial of service vulnerability exists in the remote configuration functionality of the Network Time Protocol. A specially crafted configuration file could cause an endless loop resulting in a denial of service. An attacker could provide a the malicious configuration file to trigger this vulnerability.

External References:

http://talosintel.com/reports/TALOS-2015-0055/
http://support.ntp.org/bin/view/Main/SecurityNotice#October_2015_NTP_Security_Vulner

Comment 1 Martin Prpič 2015-10-23 09:12:50 UTC

Upstream patch:

https://github.com/ntp-project/ntp/commit/bb928ef08eec020ef6008f3a140702ccc0536b8e

Comment 3 Martin Prpič 2016-01-06 13:58:13 UTC

Created ntp tracking bugs for this issue:

Affects: fedora-all [bug 1296167]

Comment 5 Martin Prpič 2016-01-07 12:07:18 UTC

Closing this as notabug:

The issue relies on the fact that an attacker could provide a crafted config file that could cause ntpd loop infinitely. Fixing this one case does not prevent the attacker from pointing ntpd to the e.g. /dev/zero file, which would have the same effect. This issue is limited to users who are able to use the :config command.