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Date:         Mon, 20 Nov 2000 13:29:17 -0800
From: FreeBSD Security Advisories <security-advisories@FREEBSD.ORG>
Subject:      FreeBSD Ports Security Advisory: FreeBSD-SA-00:73.thttpd
To: BUGTRAQ@SECURITYFOCUS.COM

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FreeBSD-SA-00:73                                           Security Advisory
                                                                FreeBSD, Inc.

Topic:          thttpd allows remote reading of local files

Category:       ports
Module:         thttpd
Announced:      2000-11-20
Credits:        ghandi@MINDLESS.COM
Affects:        Ports collection prior to the correction date.
Corrected:      2000-10-30
Vendor status:  Updated version released
FreeBSD only:   NO

I.   Background

thttpd is a simple, small, fast HTTP server.

II.  Problem Description

The thttpd port, versions prior to 2.20, allows remote viewing of
arbitrary files on the local server.  The 'ssi' cgi script does not
correctly restrict URL-encoded requests containing ".." in the path.
In addition, the cgi script does not have the same restrictions as the
web server for preventing requests outside of the web root.  These two
flaws allow remote users to access any file on the system accessible
to the web server user (user 'nobody' in the default configuration).

The thttpd 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 4100 third-party applications in a ready-to-install
format.  The ports collections shipped with FreeBSD 3.5.1 and 4.1.1
contain this problem since it was discovered after the releases, but
it was corrected prior to the release of FreeBSD 4.2.

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 may access any file on the system accessible to the web
server user (user 'nobody' in the default installation).

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

IV.  Workaround

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

V.   Solution

One of the following:

1) Upgrade your entire ports collection and rebuild the thttpd 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/www/thttpd-2.20b.tgz
ftp://ftp.FreeBSD.org/pub/FreeBSD/ports/i386/packages-4-stable/www/thttpd-2.20b.tgz
ftp://ftp.FreeBSD.org/pub/FreeBSD/ports/alpha/packages-4-stable/www/thttpd-2.20b.tgz
ftp://ftp.FreeBSD.org/pub/FreeBSD/ports/i386/packages-5-current/www/thttpd-2.20b.tgz
ftp://ftp.FreeBSD.org/pub/FreeBSD/ports/alpha/packages-5-current/www/thttpd-2.20b.tgz

3) download a new port skeleton for the thttpd 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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