RE: FreeBSD 4.6 sikkerhed

From: Laust S. Jespersen (none@L--ust.dk.lh.bsd-dk.dk)
Date: Mon 15 Jul 2002 - 19:49:53 CEST


From: "Laust S. Jespersen" <none@L--ust.dk.lh.bsd-dk.dk>
To: <none@bsd-dk--bsd-dk.dk.lh.bsd-dk.dk>
Subject: RE: FreeBSD 4.6 sikkerhed
Date: Mon, 15 Jul 2002 19:49:53 +0200

Hej Daniel!

Kører du da CURRENT? ellers er det ikke et issue.
:)

/Laust
-----Original Message-----
From: owner-bsd-dk@bsd-dk.dk [mailto:owner-bsd-dk@bsd-dk.dk]On Behalf Of
Daniel Blankensteiner
Sent: 15. juli 2002 19:24
To: bsd-dk@bsd-dk.dk
Subject: FreeBSD 4.6 sikkerhed

Uha nej ikke igen. FreeBSD 4.6.1 udkommer heldigvis i overmogen:
http://www.freebsd.org/security/index.html#adv
og nu, det er helt vildt

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

============================================================================
=
FreeBSD-SA-02:31 Security
Advisory
                                                          The FreeBSD
Project

Topic: openssh contains remote vulnerability

Category: core
Module: OpenSSH
Announced: 2002-07-15
Credits: ISS X-Force <none@xforce--ISS.net.lh.bsd-dk.dk>
                Theo DeRaadt <none@deraadt--OpenBSD.org.lh.bsd-dk.dk>
Affects: FreeBSD-CURRENT between 2002-03-18 and 2002-06-25
Corrected: 2002-06-25 19:10:07 (HEAD)
FreeBSD only: NO

I. Background

OpenSSH is a free implementation of the SSH protocol suite, and
provides encrypted and authenticated remote login, file transfer and
command execution.

II. Problem Description

SSH clients and servers communicate by exchanging discrete messages
with a variable number of parameters. Due to the lack of sufficient
integrity checks in a portion of the server code responsible for
handling incoming SSH2_MSG_USERAUTH_INFO_RESPONSE messages, it was
possible for a malicious client to send a message that would cause the
server to overwrite portions of its memory with client-provided data.

III. Impact

An remote attacker using an SSH client modified to send carefully
crafted SSH2_MSG_USERAUTH_INFO_RESPONSE to the server could obtain
superuser privileges on the server.

Please note that this problem only affects FreeBSD-CURRENT. No
versions of FreeBSD-STABLE are or were ever vulnerable to this bug.

IV. Workaround

Do one of the following:

1) Disable SSH entirely.

2) Use a firewall to block incoming SSH connections from untrusted
   hosts.

3) Add the following line to /etc/ssh/sshd_config, and restart sshd.

ChallengeResponseAuthentication no

   Note that this will prevent the use of OPIE and similar challenge-
   based authentication methods with SSH.

V. Solution

Update your system to the latest -CURRENT.

VI. Correction details

No correction details are provided in this advisory.

VII. References

<URL:http://www.openssh.com/txt/preauth.adv>
<URL:http://www.iss.net/security_center/static/9169.php>
-----BEGIN PGP SIGNATURE-----
Version: GnuPG v1.0.7 (FreeBSD)
Comment: FreeBSD: The Power To Serve

iQCVAwUBPTLiBVUuHi5z0oilAQFNAwQAoF1azTbsIiUc9O2VvIah+ueT5N3//qgf
ka+t5I5FtL8wFDKJXXf3JWx9lqf+JkscrL4SpMyY/OmL2wagvUeVHan+pE9dXRnK
YzFjdD8hP3GMiC1g0Dvwg9StoBs8kx+qP8dascS87Ql2QYo7aYcq6aageLSoy4Nj
iRHaJB2gZP8=
=nSnf
-----END PGP SIGNATURE-----

To Unsubscribe: send mail to majordomo@FreeBSD.org
with "unsubscribe freebsd-security-notifications" in the body of the message



This archive was generated by hypermail 2b30 : Wed 15 Nov 2006 - 18:24:21 CET