Bug 235882 (CVE-2007-1856)

Summary:	CVE-2007-1856 crontab denial of service
Product:	[Other] Security Response	Reporter:	Josh Bressers <bressers>
Component:	vulnerability	Assignee:	Marcela Mašláňová <mmaslano>
Status:	CLOSED CURRENTRELEASE	QA Contact:	Brock Organ <borgan>
Severity:	medium	Docs Contact:
Priority:	medium
Version:	unspecified	Keywords:	Reopened, Security
Target Milestone:	---
Target Release:	---
Hardware:	All
OS:	Linux
Whiteboard:
Fixed In Version:	vixie-cron-4.1-69	Doc Type:	Bug Fix
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2007-08-06 07:17:13 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:

Description Josh Bressers 2007-04-10 16:54:09 UTC

+++ This bug was initially created as a clone of Bug #235880 +++

Raphael Marichez of Gentoo reported a denial of service flaw in vixie-cron.

By creating a hardlink to /etc/crontab, cron will stop executing the
/etc/crontab file and deposit an error message in /var/log/cron.

This can be easily tested by running:
ln /etc/crontab /tmp/crontab
tail -f /var/log/cron


Here is the patch from Open Wall Linux:
http://cvsweb.openwall.com/cgi/cvsweb.cgi/~checkout~/Owl/packages/vixie-cron/vixie-cron-4.1.20060426-owl-st_nlink.diff?rev=1.1;content-type=text%2Fplain

This flaw also affects FC5

Comment 1 Marcela Mašláňová 2007-04-10 21:02:18 UTC

Thanks for patch. Fixed in vixie-cron-4.1-81

Comment 2 Lubomir Kundrak 2007-08-02 12:34:40 UTC

Reopening, as this is an unfixed security issue.
Marcela: please push the fixed version into FC6.

Comment 3 Marcela Mašláňová 2007-08-06 07:17:13 UTC

Fixed in update vixie-cron-4.1-69.