Bug 680798 – CVE-2011-1098 logrotate: TOCTOU race condition by creation of new files (between opening the file and moment, final permissions have been applied) [information disclosure]

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Bug 680798 - (CVE-2011-1098) CVE-2011-1098 logrotate: TOCTOU race condition by creation of new files (between opening the file and moment, final permissions have been applied) [information disclosure]

Summary:	CVE-2011-1098 logrotate: TOCTOU race condition by creation of new files (betw...

Status:	CLOSED ERRATA

Aliases:	CVE-2011-1098

Product:	Security Response
Classification:	Other
Component:	vulnerability (Show other bugs)
Sub Component:
Version:	unspecified
Hardware:	All Linux

Priority	low Severity low
Target Milestone:	---
Target Release:	---
Assigned To:	Red Hat Product Security
QA Contact:
Docs Contact:

URL:
Whiteboard:	impact=low,public=20110213,reported=2...
Keywords:	Security

Depends On:	688518 688519 688520
Blocks:
	Show dependency tree / graph

Reported:	2011-02-27 14:41 EST by Jan Lieskovsky
Modified:	2016-03-04 06:35 EST (History)
CC List:	5 users (show)

See Also:
Fixed In Version:
Doc Type:	Bug Fix
Doc Text:
Story Points:	---
Clone Of:
Environment:
Last Closed:	2015-07-30 09:14:03 EDT
Type:	---
Regression:	---
Mount Type:	---
Documentation:	---
CRM:
Verified Versions:
Category:	---
oVirt Team:	---
RHEL 7.3 requirements from Atomic Host:
Cloudforms Team:	---

Attachments	(Terms of Use)
proposed patch (1.75 KB, patch) 2011-03-16 07:02 EDT, Jan Kaluža	no flags	Details \| Diff
Add an attachment (proposed patch, testcase, etc.)

External Trackers
Tracker	ID	Priority	Status	Summary	Last Updated
Red Hat Product Errata	RHSA-2011:0407	normal	SHIPPED_LIVE	Moderate: logrotate security update	2011-03-31 11:16:26 EDT

Groups: None (edit)

Description Jan Lieskovsky 2011-02-27 14:41:45 EST

It was found that logrotate utility used insecure default
permissions, when creating of new files (time-of-check,
time-of-use, TOCTOU race condition). In some specific
configurations, a local attacker could use this flaw to
open the new file before the final permissions have been
applied, leading to disclosure of sensitive information.

Comment 3 Jan Lieskovsky 2011-03-03 05:44:32 EST

Further flaw details from Stefan Fritsch of Debian Security Team:
==================================================================

The race is between

192 fd = open(fileName, flags, sb->st_mode);

and

198 if (fchmod(fd, (S_IRUSR | S_IWUSR) & sb->st_mode)) {

and later

204 if (fchown(fd, sb->st_uid, sb->st_gid)) {


An attacker may be able to open the newly created file after line 192,
even if he has no permissions to open the file after lines 198 and 204
have been executed. Once he has the open file descriptor, he can read
what will be written into the file. No symlink attack is needed.

Comment 4 Huzaifa S. Sidhpurwala 2011-03-11 01:28:08 EST

This has been assigned CVE-2011-1098

Comment 8 Jan Kaluža 2011-03-16 07:02:53 EDT

Created attachment 485707 [details]
proposed patch

This patch fixes the issue by creating temp file with umask 0000, then change owner/mode and renames it to log file.

Upstream fixed it by use of "su" directive patch described in Bug
680799 Comment 2, but this patch breaks backward compatibility for some configurations. Attached patch is possible workaround which keeps backward compatibility.

Comment 10 Huzaifa S. Sidhpurwala 2011-03-17 05:53:11 EDT

Created logrotate tracking bugs for this issue

Affects: fedora-all [bug 688520]

Comment 11 errata-xmlrpc 2011-03-31 11:16:37 EDT

This issue has been addressed in following products:

  Red Hat Enterprise Linux 6

Via RHSA-2011:0407 https://rhn.redhat.com/errata/RHSA-2011-0407.html

Comment 13 Josh Bressers 2011-06-29 13:42:12 EDT

Statement:

The Red Hat Security Response Team has rated this issue as having low security impact, a future update may address this flaw.

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