Bugtraq: NetBSD Security Advisory 2003-003 Buffer Overflow in file(1)

From: NetBSD Security Officer <security-officer_at_netbsd.org>
Date: Wed, 12 Mar 2003 11:59:03 -0500

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NetBSD Security Advisory 2003-003
=================================

Topic: Buffer Overflow in file(1)

Version: NetBSD-current: source prior to February 27, 2003
                NetBSD 1.6: affected
                NetBSD-1.5.3: affected
                NetBSD-1.5.2: affected
                NetBSD-1.5.1: affected
                NetBSD-1.5: affected

Severity: Inducing a user to run file(1) could execute code as the user

Fixed: NetBSD-current: February 26, 2003
NetBSD-1.6 branch: March 8, 2003 (1.6.1 includes the fix)
NetBSD-1.5 branch: March 9, 2003 (1.5.4 includes the fix)

Abstract
========

If file(1) is run over a specially constructed ELF file, an exploitable
stack overflow occurs and attackers can gain the privileges of the user
running file(1).

Technical Details
=================

A buffer overflow has been found in the file(1) program. If a user
were to run file(1) over a specially doctored ELF file, arbitrary code
would be executed as a result. Thus, if an attacker can somehow induce
a user to run file(1) over a file the attacker controls, the attacker
may gain any system privileges the victim possesses.

See iDEFENSE Security Advisory 03.04.03
http://www.idefense.com/advisory/03.04.03.txt

Solutions and Workarounds
=========================

The following instructions describe how to upgrade your file(1)
binaries by updating your source tree and rebuilding and
installing a new version of file(1).

* NetBSD-current:

Systems running NetBSD-current dated from before 2003-02-27
should be upgraded to NetBSD-current dated 2003-02-27 or later.

        The following files need to be updated from the netbsd-current
        CVS branch (aka HEAD) to the respective revisions:
                src/usr.bin/file/readelf.c: 1.17
                src/usr.bin/file/softmagic.c: 1.31

        To update from CVS, re-build, and re-install file:
                # cd src
                # cvs update -d -A -P usr.bin/file
                # cd usr.bin/file

# make cleandir dependall
# make install

* NetBSD 1.6:

The binary distribution of NetBSD 1.6 is vulnerable.

        Systems running NetBSD 1.6 sources dated from before
        2003-03-09 should be upgraded from NetBSD 1.6 sources dated
        2003-03-09 or later.

NetBSD 1.6.1 will include the fix.

        The following files need to be updated from the netbsd-1-6
        CVS branch to the respective revisions:
                src/usr.bin/file/readelf.c: 1.13.2.1
                src/usr.bin/file/softmagic.c: 1.26.2.1

        To update from CVS, re-build, and re-install file:
                # cd src
                # cvs update -d -r netbsd-1-6 -P usr.bin/file
                # cd usr.bin/file

# make cleandir dependall
# make install

* NetBSD 1.5, 1.5.1, 1.5.2, 1.5.3:

The binary distribution of NetBSD 1.5.3 is vulnerable.

        Systems running NetBSD 1.5, 1.5.1, 1.5.2, or 1.5.3 sources dated
        from before 2003-03-10 should be upgraded from NetBSD 1.5.*
        sources dated 2003-03-10 or later.

        The following files need to be updated from the netbsd-1-5
        CVS branch to the respective revisions:
                src/usr.bin/file/readelf.c: 1.6.4.3
                src/usr.bin/file/softmagic.c: 1.18.4.2

        To update from CVS, re-build, and re-install file:
                # cd src
                # cvs update -d -r netbsd-1-5 -P usr.bin/file
                # cd usr.bin/file

# make cleandir dependall
# make install

Thanks To
=========

Lubomir Sedlacik and Antti Kantee, for drawing our attention to the
problem.

Christos Zoulas, for aiding in the solution and with this advisory.

Revision History
================

2003-03-12 Initial release

More Information
================

Advisories may be updated as new information becomes available.
The most recent version of this advisory (PGP signed) can be found at
ftp://ftp.netbsd.org/pub/NetBSD/security/advisories/NetBSD-SA2003-003.txt.asc

Information about NetBSD and NetBSD security can be found at
http://www.NetBSD.ORG/ and http://www.NetBSD.ORG/Security/.

$NetBSD: NetBSD-SA2003-003.txt,v 1.7 2003/03/12 03:51:31 david Exp $

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Received on Mar 12 2003