-----BEGIN PGP SIGNED MESSAGE-----

===========================================================================
              AUSCERT External Security Bulletin Redistribution
                             
                      ESB-2000.336 -- FreeBSD-SA-00:67
                 gnupg fails to correctly verify signatures
                              14 November 2000

===========================================================================

	AusCERT Security Bulletin Summary
	---------------------------------

Product:                GnuPG
Vendor:                 FreeBSD Ports Collection
Operating System:       FreeBSD
                        Unix
Impact:                 Provide Misleading Information

Ref:			ESB-2000.302

- --------------------------BEGIN INCLUDED TEXT--------------------

- -----BEGIN PGP SIGNED MESSAGE-----

=============================================================================
FreeBSD-SA-00:67                                           Security Advisory
                                                                FreeBSD, Inc.

Topic:          gnupg fails to correctly verify signatures

Category:       ports
Module:         gnupg
Announced:      2000-11-10
Credits:        Jim Small <cavenewt@MY-DEJA.COM>
Affects:        Ports collection prior to the correction date.
Corrected:      2000-10-18
Vendor status:  Updated version released
FreeBSD only:   NO

I.   Background

GnuPG is an implementation of the PGP digital signature/encryption
protocol.

II.  Problem Description

Versions of gnupg prior to 1.04 fail to correctly verify multiple
signatures contained in a single document. Only the first signature
encountered is actually verified, meaning that other data with invalid
signatures (e.g. data which has been tampered with by an attacker)
will not be verified, and the entire document will be treated as
having valid signatures.

The gnupg 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 are
vulnerable to 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

Documents containing multiple signed regions of data can be corrupted
or tampered with by an attacker without detection, as long as the
first signature in the document remains valid.

IV.  Workaround

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

V.   Solution

One of the following:

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

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

ftp://ftp.FreeBSD.org/pub/FreeBSD/ports/i386/packages-3-stable/security/gnupg-1.04.tgz
ftp://ftp.FreeBSD.org/pub/FreeBSD/ports/i386/packages-4-stable/security/gnupg-1.04.tgz
ftp://ftp.FreeBSD.org/pub/FreeBSD/ports/alpha/packages-4-stable/security/gnupg-1.04.tgz
ftp://ftp.FreeBSD.org/pub/FreeBSD/ports/i386/packages-5-current/security/gnupg-1.04.tgz
ftp://ftp.FreeBSD.org/pub/FreeBSD/ports/alpha/packages-5-current/security/gnupg-1.04.tgz

3) download a new port skeleton for the gnupg 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
- -----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.0.4 (FreeBSD)
Comment: For info see http://www.gnupg.org

iQCVAwUBOgx6dlUuHi5z0oilAQEGaAP+KXIJlLBgF7tXXtLWcyJkhI6mAxgMyHEJ
y+9RkI22mz7etMN1Nqm22Rj1cYBO99Q35lx4qJpuGftuRV+D9P6f5FbXMp+qhw24
K1t07eQhgiiNO1y9snvvEwwWtsHiosMFyIleFdbJwXoioqNsDFcByOwbG7zoEOOU
BfDBTmKtPvQ=
=1ZMA
- -----END PGP SIGNATURE-----

- --------------------------END INCLUDED TEXT--------------------

This security bulletin is provided as a service to AusCERT's members.  As
AusCERT did not write the document quoted above, AusCERT has had no control
over its content.  The decision to use any or all of this information is
the responsibility of each user or organisation, and should be done so in
accordance with site policies and procedures.

NOTE: This is only the original release of the security bulletin.  It may
not be updated when updates to the original are made.  If downloading at
a later date, it is recommended that the bulletin is retrieved directly
from the original authors to ensure that the information is still current.

Contact information for the authors of the original document is included
in the Security Bulletin above.  If you have any questions or need further
information, please contact them directly.

Previous advisories and external security bulletins can be retrieved from:

	http://www.auscert.org.au/Information/advisories.html

If you believe that your system has been compromised, contact AusCERT or
your representative in FIRST (Forum of Incident Response and Security
Teams).

Internet Email: auscert@auscert.org.au
Facsimile:	(07) 3365 7031
Telephone:	(07) 3365 4417 (International: +61 7 3365 4417)
		AusCERT personnel answer during Queensland business hours
		which are GMT+10:00 (AEST).
		On call after hours for emergencies.


-----BEGIN PGP SIGNATURE-----
Version: 2.6.3i
Charset: noconv
Comment: ftp://ftp.auscert.org.au/pub/auscert/AUSCERT_PGP.key

iQCVAwUBOlSNMSh9+71yA2DNAQGCQQP/ZU1YMyUZ9w/JWVxRSi0u8R0q1HLnHKIx
yRdsRGuQmW/Dz40UHiK+NcRoxFHlqv/RoDxMyx1tPAU2CZv3/X4cdUASm65sdDnm
TY0tHnmkGLRpkQZiasWtGcgH52YFbpbQmaii+n8GtKU76rc87hSvImhydg0GH945
4UntrZxnhf8=
=4MRN
-----END PGP SIGNATURE-----