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

2. 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 (This email address is being protected from spambots. You need JavaScript enabled to view it.) for noting the vulnerability and providing patches.

3. Bug IDs fixed: (see bugzilla for more information)

4. Relevant releases/architectures:
Red Hat Linux 6.1:
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.

5. Obsoleted by:
None

6. Conflicts with:
None

7. RPMs required:

Intel:

sysklogd-1.3.31-14.i386.rpm

Source:

sysklogd-1.3.31-14.src.rpm

8. 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.

9. Verification:

 MD5 sum                           Package Name

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

 

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

Note that you need RPM >= 3.0 to check GnuPG keys.

10. References: