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TurboLinux Security Announcement: Bind: All versions previous to 8.2.3

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February 23, 2001

Date: Thu, 22 Feb 2001 14:11:43 -0800
From: security@turbolinux.com
To: tl-security-announce@www1.turbolinux.com
Subject: [TL-Security-Announce] Bind-8.2.3-2 TLSA2001004-1

                     TurboLinux Security Announcement

        Package:  Bind
        Vulnerable Packages: All versions previous to 8.2.3
        Date: 02/21/2001 5:00 PDT

        Affected TurboLinux versions:TL 6.1 WorkStation,
                                     All TurboLinux versions
                                     6.0.5 and earlier

        TurboLinux Advisory ID#:  TLSA2001004-1

   Credits: Vulnerabilities discovered by the COVERT Labs at PGP Security
            and Claudio Musmarra.  Also, special thanks to Andrew
            Cameron for sending an email notifying
            us of this issue.

Two vulnerabilities have been discovered in ISC BIND 8. Please
update the packages in your installation as soon as possible.

1. Problem Summary(From the CERT/CC, CERT Advisory
CA-2001-02)

A. ISC BIND 8 contains a buffer overflow in transaction
signature (TSIG) handling code.

During the processing of a transaction signature (TSIG), BIND 8
checks for the presence of TSIGs that fail to include a valid key.
If such a TSIG is found, BIND skips normal processing of the
request and jumps directly to code designed to send an error
response. Because the error- handling code initializes variables
differently than in normal processing it invalidates the
assumptions that later function calls make about the size of the
request buffer.

Once these assumptions are invalidated, the code that adds a new
(valid) signature to the responses may overflow the request buffer
and overwrite adjacent memory on the stack or the heap. When
combined with other buffer overflow exploitation techniques, an
attacker can gain unauthorized privileged access to the system,
allowing the execution of arbitrary code.

B. Queries to ISC BIND servers may disclose environment
variables

This vulnerability is an information leak in the query
processing code of BIND 8 that allows a remote attacker to access
the program stack, possibly exposing program and/or environment
variables. This vulnerability is triggered by sending a specially
formatted query to vulnerable BIND servers.

2. Impact(From CERT/CC, CERT Advisory CA-2001-02)

A. ISC BIND 8 contains buffer overflow in transaction signature
(TSIG) handling code

This vulnerability may allow an attacker to execute code with
the same privileges as the BIND server. Because BIND is typically
run by a superuser account, the execution would occur with
superuser privileges.

B. Queries to ISC BIND servers may disclose environment
variables

This vulnerability may allow attackers to read information from
the program stack, possibly exposing environment variables.

3. Solution

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

rpm -Uvh ftp_path_to_filename

Where ftp_path_to_filename is the following:

ftp://ftp.turbolinux.com/pub/updates/6.0/security/bind-8.2.3-2.i386.rpm

ftp://ftp.turbolinux.com/pub/updates/6.0/security/bind-contrib-8.2.3-2.i386.rpm

ftp://ftp.turbolinux.com/pub/updates/6.0/security/bind-devel-8.2.3-2.i386.rpm

ftp://ftp.turbolinux.com/pub/updates/6.0/security/bind-utils-8.2.3-2.i386.rpm

The source RPM can be downloaded here:

ftp://ftp.turbolinux.com/pub/updates/6.0/SRPMS/bind-8.2.3-2.src.rpm

**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 THE SECURITY HOLE.

Please verify the MD5 checksums of the updates before you
install:

  MD5 sum                               Package Name

dec967e3a1dd16bdcca0c6fe6e9114d6 bind-8.2.3-2.i386.rpm
2e84bbbcd6a09d7c5060dd01480ff3de bind-contrib-8.2.3-2.i386.rpm
06612093126372f8d618ea842fd402ec bind-devel-8.2.3-2.i386.rpm
3f390ce4d1b7ceaa477df62cc3fe3174 bind-utils-8.2.3-2.i386.rpm
25c701c7158af3f773d1a478c8872d05 bind-8.2.3-2.src.rpm

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

http://www.turbolinux.com/security/tlgpgkey.asc

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:

http://www.turbolinux.com/security

If you want to report vulnerabilities, please contact: