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Subject: [TL-Security-Announce] xlockmore TLSA2000012-1.txt
From: Katherine M. Moussouris (k8eTURBOLINUX.COM)
Date: Tue May 30 2000 - 16:46:08 CDT

Hash: SHA1


                        TurboLinux Security Announcement

        Package: xlockmore-4.16 and earlier
        Date: Mon May 29 20:29:06 PDT 2000

        Affected TurboLinux versions: 6.0.4 and earlier; 6.0.5 NOT affected
        Vulnerability Type: local users can view shadowed password file
         TurboLinux Advisory ID#: TLSA2000012-1

        Credits: This vulnerability was discovered by COVERT labs at
        Network Associates, Inc., published to BUGTRAQ Mon, 29 May 2000.

A security hole was discovered in the package mentioned above.
Please update the package in your installation as soon as possible or
disable the service.

1. Problem Summary

   From the COVERT labs NAI advisory:

   "The xlock program locks an X server until a valid password is entered.
   The command line option -mode provides a user with a mechanism to
   change the default display shown when the X server is locked. xlock
   is installed with privileges to obtain password information, although
   these are dropped as early as possible. An overflow in the -mode
   command line option allows a malicious attacker to reveal arbitrary
   portions of xlock's address space including the shadow password file."

2. Impact

   A local user can use the overflow to read the shadowed password file.

3. Solution

  Update the package from our ftp server by running the following command:

  rpm -Fvh ftp_path_to_filename

  Where ftp_path_to_filename is the following:


  The source RPM can be downloaded here:


  **Note: You must rebuild and install the RPM if you choose to download
  and install the SRPM. Simply installing the SRPM alone WILL NOT CLOSE

  Please verify the MD5 checksum of the update before you install:

  MD5 sum Package Name
- ------------------------------------------------------------
4987a64d63c0e803e61df11c106d33a3 xlockmore-4.16.1-1.i386.rpm

fc29032bbef8b9d111b9cadd43954ecc xlockmore-4.16.1-1.src.rpm

These packages are GPG signed by Turbolinux for security. Our key
is available here:


To verify a package, use the following command:

 rpm --checksig name_of_rpm

To examine only the md5sum, use the following command:

 rpm --checksig --nogpg name_of_rpm

**Note: Checking GPG keys requires RPM 3.0 or higher.

You can find more updates on our ftp server:

   ftp://ftp.turbolinux.com/pub/updates/6.0/security/ for TL6.0 Workstation
   and Server security updates
   ftp://ftp.turbolinux.com/pub/updates/4.0/security/ for TL4.0 Workstation
   and Server security updates

Our webpage for security announcements:


If you want to report vulnerabilities, please contact:


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  Subscribe at http://www.turbolinux.com/mailman/listinfo/tl-security

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  and alerts.
  Subscribe at http://www.turbolinux.com/mailman/listinfo/tl-security-announce
Version: GnuPG v1.0.1 (GNU/Linux)
Comment: For info see http://www.gnupg.org


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