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TUCoPS :: BSD :: ciacl004.htm
FreeBSD LPRng Vulnerability

FreeBSD LPRng Vulnerability Privacy and Legal Notice CIAC INFORMATION BULLETIN L-004: FreeBSD LPRng Vulnerability October 13, 2000 19:00 GMT

PROBLEM:       A vulnerability exists in the 'syslog(3) function of LPRng,
               versions prior to 3.6.24.
PLATFORM:      FreeBSD 3.5.1, 4.1, & 4.1.1
DAMAGE:        Using string-formatting operators a malicious user may
               gain root access.
SOLUTION:      Either remove the software from the system, or apply the patch
               offered by FreeBSD.
VULNERABILITY  The risk is LOW. This vulnerability is publicly known,
ASSESSMENT:    however no incidents have been reported.


[******  Begin FreeBSD Advisory ******]


FreeBSD-SA-00:56                                           Security Advisory
                                                                FreeBSD, Inc.

Topic:          LPRng contains potential root compromise

Category:       ports
Module:         LPRng
Announced:      2000-10-13
Credits:        Chris Evans 
Affects:        Ports collection prior to the correction date.
Corrected:      2000-10-13
Vendor status:  Updated version released
FreeBSD only:   NO

I.   Background

LPRng is a popular printer daemon.

II.  Problem Description

The LPRng port, versions prior to 3.6.24, contains a potential
vulnerability which may allow root compromise from both local and
remote systems. The vulnerability is due to incorrect usage of the
syslog(3) function. Local and remote users can send string-formatting
operators to the printer daemon to corrupt the daemon's execution,
potentially gaining root access.

The LPRng port is not installed by default, nor is it "part of
FreeBSD" as such: it is part of the FreeBSD ports collection, which
contains nearly 4000 third-party applications in a ready-to-install
format. The ports collections shipped with FreeBSD 3.5.1, 4.1 and
4.1.1 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

Local and remote users may potentially gain root privileges on systems
using LPRng.

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

IV.  Workaround

Deinstall the LPRng port/package, if you you have installed it.

V.   Solution

One of the following:

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

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

ftp://ftp.FreeBSD.org/pub/FreeBSD/ports/i386/packages-3-stable/sysutils/LPRng-3.6.25.t
ftp://ftp.FreeBSD.org/pub/FreeBSD/ports/i386/packages-4-stable/sysutils/LPRng-3.6.25.tgz
ftp://ftp.FreeBSD.org/pub/FreeBSD/ports/alpha/packages-4-stable/sysutils/LPRng-3.6.25.tgz
ftp://ftp.FreeBSD.org/pub/FreeBSD/ports/i386/packages-5-current/sysutils/LPRng-3.6.25.tgz
ftp://ftp.FreeBSD.org/pub/FreeBSD/ports/alpha/packages-5-current/sysutils/LPRng-3.6.25.tgz

NOTE: It may be several days before updated packages are available.

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

 http://www.freebsd.org/ports/

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:

ftp://ftp.FreeBSD.org/pub/FreeBSD/ports/i386/packages-3-stable/devel/portcheckout-2.0.tgz
ftp://ftp.FreeBSD.org/pub/FreeBSD/ports/i386/packages-4-stable/devel/portcheckout-2.0.tgz
ftp://ftp.FreeBSD.org/pub/FreeBSD/ports/alpha/packages-4-stable/devel/portcheckout-2.0.tgz
ftp://ftp.FreeBSD.org/pub/FreeBSD/ports/i386/packages-5-current/devel/portcheckout-2.0.tgz
ftp://ftp.FreeBSD.org/pub/FreeBSD/ports/alpha/packages-5-
current/devel/portcheckout-2.0.tgz

[******  End FreeBSD Advisory ******]

CIAC wishes to acknowledge the contributions of FreeBSD, Inc. for the information contained in this bulletin.

CIAC services are available to DOE, DOE Contractors, and the NIH. CIAC can be contacted at:

    Voice:          +1 925-422-8193 (7 x 24)
    FAX:            +1 925-423-8002
    STU-III:        +1 925-423-2604
    E-mail:          ciac@llnl.gov
    World Wide Web:  http://www.ciac.org/
                     http://ciac.llnl.gov
                     (same machine -- either one will work)
    Anonymous FTP:   ftp.ciac.org
                     ciac.llnl.gov
                     (same machine -- either one will work)

This document was prepared as an account of work sponsored by an agency of the United States Government. Neither the United States Government nor the University of California nor any of their employees, makes any warranty, express or implied, or assumes any legal liability or responsibility for the accuracy, completeness, or usefulness of any information, apparatus, product, or process disclosed, or represents that its use would not infringe privately owned rights. Reference herein to any specific commercial products, process, or service by trade name, trademark, manufacturer, or otherwise, does not necessarily constitute or imply its endorsement, recommendation or favoring by the United States Government or the University of California. The views and opinions of authors expressed herein do not necessarily state or reflect those of the United States Government or the University of California, and shall not be used for advertising or product endorsement purposes.

UCRL-MI-119788
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