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Old May 19th, 2008, 04:01 PM
Mikorist's Avatar
Mikorist Mikorist is offline
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Join Date: Dec 2006
O/S: Linux
Location: Belgrade (Serbia)
Age: 50
Posts: 40
Exclamation OpenSSL bug found in Debian Linux

Debian Linux got a bit of a black eye this week with the announcement that a
nasty cryptographic vulnerability exists in its version of the OpenSSL package.




Package..............: openssl
Vulnerability........: predictable random number generator
Problem type.......: remote
Debian-specific....:yes
CVE Id(s)............: CVE-2008-0166
Site.....................:http://www.debian.org/security/

Luciano Bello discovered that the random number generator in Debian's
openssl package is predictable. This is caused by an incorrect
Debian-specific change to the openssl package (CVE-2008-0166). As a
result, cryptographic key material may be guessable.

This is a Debian-specific vulnerability which does not affect other
operating systems which are not based on Debian. However, other systems
can be indirectly affected if weak keys are imported into them.

It is strongly recommended that all cryptographic key material which has
been generated by OpenSSL versions starting with 0.9.8c-1 on Debian
systems is recreated from scratch. Furthermore, all DSA keys ever used
on affected Debian systems for signing or authentication purposes should
be considered compromised; the Digital Signature Algorithm relies on a
secret random value used during signature generation.

The first vulnerable version, 0.9.8c-1, was uploaded to the unstable
distribution on 2006-09-17, and has since propagated to the testing and
current stable (etch) distributions. The old stable distribution
(sarge) is not affected.

Affected keys include SSH keys, OpenVPN keys, DNSSEC keys, and key
material for use in X.509 certificates and session keys used in SSL/TLS
connections. Keys generated with GnuPG or GNUTLS are not affected,
though.


Check your system:

Code:
ssh-keyscan -t rsa HOSTNAME | ssh-vulnkey -
If you have something like this:


~$ ssh-keyscan -t rsa localhost | ssh-vulnkey -
# localhost SSH-2.0-OpenSSH_4.3p2 Debian-9
# COMPROMISED: 2048 16:1a:35:c4:4e:c6:d0:bf:0c:87:26:19:59:57:ac:6d -

OpenSSL is 100% COMPROMISED

The solution? Upgrade OpenSSL and re-generate all your SSH and SSL keys. This problem not only affects Debian, but also all its derivatives, such as Ubuntu.

Upgrade instructions
---------------------


Code:
~# apt-get update
		will update the internal database

~# apt-get install openssh-server
		will install corrected packages

The following NEW packages will be installed:
openssh-blacklist
The following packages will be upgraded:
libssl0.9.8 openssh-client openssh-server

Setting up openssh-server (4.3p2-9etch2) …
Creating SSH2 RSA key; this may take some time …
Creating SSH2 DSA key; this may take some time …
Restarting OpenBSD Secure Shell server: sshd.

-------------------------------


Mikorist

Last edited by Mikorist; May 19th, 2008 at 04:10 PM.
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