Operating System:

Published:

21 November 1999

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===========================================================================
              AUSCERT External Security Bulletin Redistribution
                             
                      ESB-1999.176 -- RHSA-1999:055-01
                     Denial of service attack in syslogd
                              22 November 1999

===========================================================================

Red Hat Inc. has released the following advisory concerning a denial of 
service attack vulnerability in the system log daemon, syslogd.  

This vulnerability affects all Red Hat Linux 4.x, 5.x and 6.x 
architectures, however, Red Hat Linux 6.1 is not vulnerable.

This vulnerability may allow users to open a large number of connections to 
the log daemon which may constitute a denial of service.


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		   Red Hat, Inc. Security Advisory

Synopsis:		Denial of service attack in syslogd
Advisory ID:		RHSA-1999:055-01
Issue date:		1999-11-19
Updated on:		1999-11-19	
Keywords:		syslogd sysklogd stream socket
Cross references:	bugtraq id #809
- ---------------------------------------------------------------------

1. Topic:

A denial of service attack exists in the system log daemon, syslogd.

2. Relevant releases/architectures:

Red Hat Linux 4.x, all architectures
Red Hat Linux 5.x, all architectures
Red Hat Linux 6.0, all architectures

Red Hat Linux 6.1 is not vulnerable to this security issue. However,
users of Red Hat Linux 6.1/Intel may wish to upgrade to the latest
package to fix a problem in the syslog daemon where log connections
would be reset after the syslog daemon is restarted.

3. Problem description:

The syslog daemon by default used unix domain stream sockets for receiving
local log connections. By opening a large number of connections to
the log daemon, the user could make the system unresponsive.

Thanks go to Olaf Kirch (okir@monad.swb.de) for noting the vulnerability
and providing patches.

4. Solution:

For each RPM for your particular architecture, run:
    rpm -Uvh <filename>
where filename is the name of the RPM.

libc updates are needed for Red Hat Linux 4.2 for the Intel and Sparc
architectures so that logging will work correctly with the upgraded sysklogd
packages.

Note: Upgrading to these sysklogd packages may impair the logging abilities
of some software that does not use the standard C library syslog(3) interface
to the system logs. Such software may have to be changed to use datagram
connections instead of stream connections to the log socket.

5. Bug IDs fixed (http://developer.redhat.com/bugzilla for more info):

6. Obsoleted by:

7. Conflicts with:

8. RPMs required:

Red Hat Linux 4.x:

Intel:
  ftp://updates.redhat.com/4.2/i386/sysklogd-1.3.31-0.5.i386.rpm
  ftp://updates.redhat.com/4.2/i386/libc-5.3.12-18.5.i386.rpm
  ftp://updates.redhat.com/4.2/i386/libc-debug-5.3.12-18.5.i386.rpm
  ftp://updates.redhat.com/4.2/i386/libc-devel-5.3.12-18.5.i386.rpm
  ftp://updates.redhat.com/4.2/i386/libc-profile-5.3.12-18.5.i386.rpm
  ftp://updates.redhat.com/4.2/i386/libc-static-5.3.12-18.5.i386.rpm

Alpha:
  ftp://updates.redhat.com/4.2/alpha/sysklogd-1.3.31-0.5.alpha.rpm

Sparc:
  ftp://updates.redhat.com/4.2/sparc/sysklogd-1.3.31-0.5.sparc.rpm
  ftp://updates.redhat.com/4.2/sparc/libc-5.3.12-18.5.sparc.rpm
  ftp://updates.redhat.com/4.2/sparc/libc-debug-5.3.12-18.5.sparc.rpm
  ftp://updates.redhat.com/4.2/sparc/libc-devel-5.3.12-18.5.sparc.rpm
  ftp://updates.redhat.com/4.2/sparc/libc-profile-5.3.12-18.5.sparc.rpm
  ftp://updates.redhat.com/4.2/sparc/libc-static-5.3.12-18.5.sparc.rpm

Source packages:
  ftp://updates.redhat.com/4.2/SRPMS/sysklogd-1.3.31-0.5.src.rpm
  ftp://updates.redhat.com/4.2/SRPMS/libc-5.3.12-18.5.src.rpm

Red Hat Linux 5.x:

Intel:
  ftp://updates.redhat.com/5.2/i386/sysklogd-1.3.31-1.5.i386.rpm

Alpha:
  ftp://updates.redhat.com/5.2/alpha/sysklogd-1.3.31-1.5.alpha.rpm

Sparc:
  ftp://updates.redhat.com/5.2/sparc/sysklogd-1.3.31-1.5.sparc.rpm

Source packages:
  ftp://updates.redhat.com/5.2/SRPMS/sysklogd-1.3.31-1.5.src.rpm

Red Hat Linux 6.0:

Intel:
  ftp://updates.redhat.com/6.0/i386/sysklogd-1.3.31-14.i386.rpm

Alpha:
  ftp://updates.redhat.com/6.0/alpha/sysklogd-1.3.31-14.alpha.rpm

Sparc:
  ftp://updates.redhat.com/6.0/sparc/sysklogd-1.3.31-14.sparc.rpm

Source packages:
  ftp://updates.redhat.com/6.0/SRPMS/sysklogd-1.3.31-14.src.rpm

Red Hat Linux 6.1:

Intel:
  ftp://updates.redhat.com/6.1/i386/sysklogd-1.3.31-14.i386.rpm

Source packages:
  ftp://updates.redhat.com/6.1/SRPMS/sysklogd-1.3.31-14.src.rpm

9. Verification:

MD5 sum                           Package Name
- --------------------------------------------------------------------------
378d0be4ef864e9106fe46349cb366b9  i386/sysklogd-1.3.31-0.5.i386.rpm
801c745d3e920d29fdea2f5be07d25b3  i386/libc-5.3.12-18.5.i386.rpm
1d5ba779311e222a824895e0a6b34516  i386/libc-debug-5.3.12-18.5.i386.rpm
bacf136ee00f323fcf0a8db95b5ab231  i386/libc-devel-5.3.12-18.5.i386.rpm
a25eb15726a1c216b3bdf9ab1b2d670c  i386/libc-profile-5.3.12-18.5.i386.rpm
62bc3f2df09cdc0abd4138b51894b6a7  i386/libc-static-5.3.12-18.5.i386.rpm
bafdc46464b2ae72739630c14e2eeb5a  alpha/sysklogd-1.3.31-0.5.alpha.rpm
f34994e1cd262f01dc5c11681a31855e  sparc/sysklogd-1.3.31-0.5.sparc.rpm
7130a7c76581cde28790638e6696d522  sparc/libc-5.3.12-18.5.sparc.rpm
f81bae231d268bd1a1a703f13fb4c140  sparc/libc-debug-5.3.12-18.5.sparc.rpm
0938e6fb074dd0769542037194ccb031  sparc/libc-devel-5.3.12-18.5.sparc.rpm
bceef7f99adc7b198f743eacd770db5b  sparc/libc-profile-5.3.12-18.5.sparc.rpm
ef2d6ecb52d6ef30fac839e3a0c4e7d0  sparc/libc-static-5.3.12-18.5.sparc.rpm
d371c2f33b29034be986b95f3acf457f  SRPMS/sysklogd-1.3.31-0.5.src.rpm
1c210bd05b6de76ee8ac8d6c40c3d1d9  SRPMS/libc-5.3.12-18.5.src.rpm

1cd398b77471d5a90c2ce64487c32be4  i386/sysklogd-1.3.31-1.5.i386.rpm
2564ea2b333d6c26024f8edefb49f295  alpha/sysklogd-1.3.31-1.5.alpha.rpm
5561ccefc3e499dba6b5eae181dde217  sparc/sysklogd-1.3.31-1.5.sparc.rpm
508762e8fd7e97c5c50372eb27eaa19c  SRPMS/sysklogd-1.3.31-1.5.src.rpm

8e59b61b8b1a9356ea675d7234b801d8  i386/sysklogd-1.3.31-14.i386.rpm
d906f40e4084ac82afe9b5a2686a167d  alpha/sysklogd-1.3.31-14.alpha.rpm
5ec7b94032e4c3a911099d7547e0742d  sparc/sysklogd-1.3.31-14.sparc.rpm
55cc22adb6b3272ef23763e89309af24  SRPMS/sysklogd-1.3.31-14.src.rpm

8e59b61b8b1a9356ea675d7234b801d8  i386/sysklogd-1.3.31-14.i386.rpm
55cc22adb6b3272ef23763e89309af24  SRPMS/sysklogd-1.3.31-14.src.rpm

These packages are GPG signed by Red Hat, Inc. for security.  Our key
is available at:
    http://www.redhat.com/corp/contact.html
 
You can verify each package with the following command:
    rpm --checksig  <filename>

If you only wish to verify that each package has not been corrupted or
tampered with, examine only the md5sum with the following command:
    rpm --checksig --nogpg <filename>

10. References:

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