FreeBSD Ports Security Advisory: FreeBSD-SA-00:40.mopd

FreeBSD Security Advisories security-advisories at
Mon Aug 28 12:43:51 PDT 2000


FreeBSD-SA-00:40                                           Security Advisory
                                                                FreeBSD, Inc.

Topic:          mopd port allows remote root compromise

Category:       ports
Module:         mopd
Announced:      2000-08-28
Credits:        Matt Power <mhpower at MIT.EDU>, OpenBSD
Affects:        Ports collection prior to the correction date.
Corrected:      2000-08-09
Vendor status:  Contacted
FreeBSD only:   NO

I.   Background

mopd is used for netbooting older DEC machines such as VAXen and

II.  Problem Description

The mopd port contains several remotely exploitable
vulnerabilities. An attacker exploiting these can execute arbitrary
code on the local machine as root.

The mopd port is not installed by default, nor is it "part of FreeBSD"
as such: it is part of the FreeBSD ports collection, which contains
over 3700 third-party applications in a ready-to-install format. The
ports collections shipped with FreeBSD 3.5-RELEASE and 4.1-RELEASE
contain this problem, since it was discovered after the releases.

FreeBSD makes no claim about the security of these third-party
applications, although an effort is underway to provide a security
audit of the most security-critical ports.

III. Impact

Remote users can execute arbitrary code on the local machine as root.

If you have not chosen to install the mopd port/package, then your
system is not vulnerable to this problem.

IV.  Workaround

One of the following:

1) Deinstall the mopd port/package, if you have installed it.

2) Restrict access to the mopd port using a perimeter firewall, or
ipfw(8)/ipf(8) on the local machine. Note that users who pass these
access restrictions may still exploit the vulnerability.

V.   Solution

One of the following:

1) Upgrade your entire ports collection and rebuild the mopd port.

2) Deinstall the old package and install a new package dated after the
correction date, obtained from:

NOTE: Be sure to check the file creation date on the package, because
the version number of the software has not changed.

3) download a new port skeleton for the mopd port from:

and use it to rebuild the port.

4) Use the portcheckout utility to automate option (3) above. The
portcheckout port is available in /usr/ports/devel/portcheckout or the
package can be obtained from:

Version: 2.6.2


This is the moderated mailing list freebsd-announce.
The list contains announcements of new FreeBSD capabilities,
important events and project milestones.
See also the FreeBSD Web pages at

To Unsubscribe: send mail to majordomo at
with "unsubscribe freebsd-announce" in the body of the message

More information about the freebsd-announce mailing list