Red Hat Linux Security Advisory
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Synopsis	Network Time Daemon (ntpd) has potential remote root exploit

Advisory ID	RHSA-2001:045-05

Issue Date	2001-04-05

Updated On	2001-04-08

Product	Red Hat Linux

Keywords	ntpd exploit buffer overflow

Cross References

Obsoletes

1. Topic:

The Network Time Daemon (ntpd) supplied with all releases of Red Hat
Linux is vulnerable to a buffer overflow, allowing a remote attacker to
potentially gain root level access to a machine. All users of ntpd are
strongly encouraged to upgrade.

2. Problem description:

The Network Time Daemon (xntpd on Red Hat Linux 6.2 and earlier, ntpd on
Red Hat Linux 7.0) does not properly check the size of a buffer used to
hold incoming data from the network. Potentially, an attacker could gain
root access by exploiting this weakness.

Potential damage is mitigated by the fact that the Network Time Daemon is
not enabled by default. If you are not using network time services, it
may not even be installed. As a general rule, Red Hat encourages users to
enable only those network services they actually need.

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

34813 - ntpd security hole

4. Relevant releases/architectures:

Red Hat Linux 5.2 - alpha, i386, sparc
Red Hat Linux 6.2 - alpha, i386, sparc
Red Hat Linux 7.0 - alpha, i386

5. RPMs required:

6. Solution:

To update all RPMs for your particular architecture, run:

rpm -Fvh [filenames]

where [filenames] is a list of the RPMs you wish to upgrade. Only those
RPMs which are currently installed will be updated. Those RPMs which are
not installed but included in the list will not be updated. Note that you
can also use wildcards (*.rpm) if your current directly *only* contains the
desired RPMs.

Please note that this update is also available via Red Hat Network. Many
people find this an easier way to apply updates. To use Red Hat Network,
launch the Red Hat Update Agent with the following command:

up2date

This will start an interactive process that will result in the appropriate
RPMs being upgraded on your system.

7. Verification:

MD5 sum                           Package Name
-------------------------------------------------------------------------
0d3566d34cd5bc9990a15a41be99e4c7 5.2/en/os/SRPMS/xntp3-5.93-14.src.rpm
aa851fdb72e9f6464e9688378617c9df 5.2/en/os/alpha/xntp3-5.93-14.alpha.rpm
176041bd0364ca91b6d7db3869c4a0a0 5.2/en/os/i386/xntp3-5.93-14.i386.rpm
9b224d8bd3640a6fbd37785c6c5d3ce2 5.2/en/os/sparc/xntp3-5.93-14.sparc.rpm
a83add134f54dd4fbdcfd0cef5929b43 6.2/en/os/SRPMS/xntp3-5.93-15.src.rpm
64d936dcf1fa8fe97a12b314923ae89c 6.2/en/os/alpha/xntp3-5.93-15.alpha.rpm
af43bc024a00586ef97265c7bf2e63df 6.2/en/os/i386/xntp3-5.93-15.i386.rpm
3f13de81debf2dc875d84c046596e27d 6.2/en/os/sparc/xntp3-5.93-15.sparc.rpm
b7f60c57e74179913ebc2dc1da04f410 7.0/en/os/SRPMS/ntp-4.0.99k-15.src.rpm
6334b7ba31606cfe04d98967adbf3350 7.0/en/os/alpha/ntp-4.0.99k-15.alpha.rpm
f67d135fd6ccadb9f36aeca4a429a9fa 7.0/en/os/i386/ntp-4.0.99k-15.i386.rpm

These packages are GPG signed by Red Hat, Inc. for security. Our key is available at:
http://www.redhat.com/about/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

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

8. References:

BugTraq Message-ID <20010404222701.X91913@riget.scene.pl>
http://www.eecis.udel.edu/~ntp/