English | Deutsch | Español | Português
 UserID:
 Passwd:
new user
 About:   Dedicated  | Advanced  | Standard  | Recurring  | No Risk  | Desktop  | Basic  | Single  | Security Seal  | FAQ
  Price/Feature Summary  | Order  | New Vulnerabilities  | Confidentiality  | Vulnerability Search
 Vulnerability   
Search   
    Search 158599 CVE descriptions
and 74190 test descriptions,
access 10,000+ cross references.
Tests   CVE   All  

-----BEGIN PGP SIGNED MESSAGE-----

=============================================================================
FreeBSD-SA-02:27.rc                                         Security Advisory
                                                          The FreeBSD Project

Topic:          rc uses file globbing dangerously

Category:       core
Module:         rc
Announced:      2002-05-29
Credits:        lumpy <lumpy@the.whole.net>
Affects:        FreeBSD 4.4-RELEASE
                FreeBSD 4.5-RELEASE
                FreeBSD 4-STABLE prior to the correction date
Corrected:      2002-05-09 17:39:01 UTC (RELENG_4)
                2002-05-09 17:40:27 UTC (RELENG_4_5)
                2002-05-09 17:41:05 UTC (RELENG_4_4)
FreeBSD only:   YES

I.   Background

rc is the system startup script (/etc/rc).  It is run when the FreeBSD
is booted multi-user, and performs a multitude of tasks to bring the
system up.  One of these tasks is to remove lock files left by X
Windows, as their existence could prevent one from restarting the X
Windows server.

II.  Problem Description

When removing X Windows lock files, rc uses the rm(1) command and
shell globbing:

   rm -f /tmp/.X*-lock /tmp/.X11-unix/*

Since /tmp is a world-writable directory, a user may create
/tmp/.X11-unix as a symbolic link to an arbitrary directory.  The next
time that rc is run (i.e. the next time the system is booted), rc will
then remove all of the files in that directory.

III. Impact

Users may remove the contents of arbitrary directories if the
/tmp/.X11-unix directory does not already exist and the system can
be enticed to reboot (or the user can wait until the next system
maintenance window).

IV.  Workaround

Find and remove or comment-out the following line in /etc/rc:

   rm -f /tmp/.X*-lock /tmp/.X11-unix/*

The following command executed as root will do this:

   /bin/sh -c 'echo -e "/.X11-unix/s/^/#/\nw\nq\n" | /bin/ed -s /etc/rc'

V.   Solution

1) Upgrade your vulnerable system to 4.5-STABLE; or to either of the
RELENG_4_5 (4.5-RELEASE-p6) or RELENG_4_4 (4.4-RELEASE-p13) security
branches dated after the respective correction dates.

2) To patch your present system:

a) Download the relevant patch from the location below, and verify the
detached PGP signature using your PGP utility.

# fetch ftp://ftp.FreeBSD.org/pub/FreeBSD/CERT/patches/SA-02:27/rc.patch
# fetch ftp://ftp.FreeBSD.org/pub/FreeBSD/CERT/patches/SA-02:27/rc.patch.asc

b) Execute the following commands as root:

# cd /usr/src
# patch < /path/to/patch

c) Install the new rc script:

# cd /usr/src/etc
# install -c -o root -g wheel -m 644 rc /etc/rc

VI.  Correction details

The following list contains the revision numbers of each file that was
corrected in FreeBSD.

Path                                                             Revision
  Branch
- -------------------------------------------------------------------------
src/etc/rc
  RELENG_4                                                     1.212.2.50
  RELENG_4_5                                               1.212.2.38.2.1
  RELENG_4_4                                               1.212.2.34.2.1
- -------------------------------------------------------------------------

VII. References

<URL:http://www.freebsd.org/cgi/cvsweb.cgi/src/etc/rc?rev=1.312&content-type=text/x-cvsweb-markup>
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.0.7 (FreeBSD)

iQCVAwUBPPUdKVUuHi5z0oilAQExLgP/boRbYHYXHXBC9YW1sf6FFFwhaY5iOYeZ
1JAHA+CZGyOas4RPgIBN6zxVPRX70KOdREp9flkgVvdOvODljk6k6TUjqE4xwTj9
wi0yS81Hp04uQfx+PwJSLdFvKIR/gr/TMWn1f1KD2Vy3nzZh6IAuCdzcg0z9AKlc
OQf5FWVpn8s=
=NaDG
-----END PGP SIGNATURE-----

New User Registration
Email:
UserID:
Passwd:
Please email me your monthly newsletters, informing the latest services, improvements & surveys.
Please email me a vulnerability test announcement whenever a new test is added.
   Privacy
Registered User Login
 
UserID:   
Passwd:  

 Forgot userid or passwd?
Email/Userid:




Home | About Us | Contact Us | Partner Programs | Developer APIs | Privacy | Mailing Lists | Abuse
Security Audits | Managed DNS | Network Monitoring | Site Analyzer | Internet Research Reports
Web Probe

© 1998-2019 E-Soft Inc. All rights reserved.