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Date:         Fri, 13 Oct 2000 09:12:02 -0700
From: FreeBSD Security Advisories <security-advisories@FREEBSD.ORG>
Subject:      FreeBSD Ports Security Advisory: FreeBSD-SA-00:55.xpdf
To: BUGTRAQ@SECURITYFOCUS.COM

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=============================================================================
FreeBSD-SA-00:55                                           Security Advisory
                                                                FreeBSD, Inc.

Topic:          xpdf contains multiple vulnerabilities

Category:       ports
Module:         xpdf
Announced:      2000-10-13
Credits:        Unknown
Affects:        Ports collection prior to the correction date.
Corrected:      2000-09-04 (4.1.1-RELEASE)
Vendor status:  Updated version released
FreeBSD only:   NO

I.   Background

xpdf is a PDF viewer for X Windows.

II.  Problem Description

The xpdf port, versions prior to 0.91, contains a race condition due
to improper handing of temporary files that may allow a local user to
overwrite arbitrary files owned by the user running xpdf.

Additionally, when handling URLs in documents no checking was done for
shell metacharacters before starting the browser. This makes it possible
to construct a document which cause xpdf to run arbitrary commands when
the user views an URL.

The xpdf 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 and 4.1 contain this
problem since it was discovered after the releases, but it was
corrected prior to the release of FreeBSD 4.1.1.

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 users, using a symlink attack, can cause arbitrary files owned
by the user running xpdf to be overwritten. Also, malicious PDFs can
cause arbitrary code to be executed.

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

IV.  Workaround

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

V.   Solution

One of the following:

1) Upgrade your entire ports collection and rebuild the xpdf 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/graphics/xpdf-0.91.tgz
ftp://ftp.FreeBSD.org/pub/FreeBSD/ports/i386/packages-4-stable/graphics/xpdf-0.91.tgz
ftp://ftp.FreeBSD.org/pub/FreeBSD/ports/alpha/packages-4-stable/graphics/xpdf-0.91.tgz
ftp://ftp.FreeBSD.org/pub/FreeBSD/ports/i386/packages-5-current/graphics/xpdf-0.91.tgz
ftp://ftp.FreeBSD.org/pub/FreeBSD/ports/alpha/packages-5-current/graphics/xpdf-0.91.tgz

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

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