DSA-086-1 ssh-nonfree -- remote root exploit

Related Vulnerabilities: CVE-2001-0361  

We have received reports that the "SSH CRC-32 compensation attack detector vulnerability" is being actively exploited. This is the same integer type error previously corrected for OpenSSH in DSA-027-1. OpenSSH (the Debian ssh package) was fixed at that time, but ssh-nonfree and ssh-socks were not. Though packages in the non-free section of the archive are not officially supported by the Debian project, we are taking the unusual step of releasing updated ssh-nonfree/ssh-socks packages for those users who have not yet migrated to OpenSSH. However, we do recommend that our users migrate to the regularly supported, DFSG-free "ssh" package as soon as possible. ssh 1.2.3-9.3 is the OpenSSH package available in Debian 2.2r4. The fixed ssh-nonfree/ssh-socks packages are available in version 1.2.27-6.2 for use with Debian 2.2 (potato) and version 1.2.27-8 for use with the Debian unstable/testing distribution. Note that the new ssh-nonfree/ssh-socks packages remove the setuid bit from the ssh binary, disabling rhosts-rsa authentication. If you need this functionality, run chmod u+s /usr/bin/ssh1 after installing the new package.

Debian Security Advisory

DSA-086-1 ssh-nonfree -- remote root exploit

Date Reported:
13 Nov 2001
Affected Packages:
ssh-nonfree, ssh-socks
Vulnerable:
Yes
Security database references:
In Mitre's CVE dictionary: CVE-2001-0361.
More information:

We have received reports that the "SSH CRC-32 compensation attack detector vulnerability" is being actively exploited. This is the same integer type error previously corrected for OpenSSH in DSA-027-1. OpenSSH (the Debian ssh package) was fixed at that time, but ssh-nonfree and ssh-socks were not.

Though packages in the non-free section of the archive are not officially supported by the Debian project, we are taking the unusual step of releasing updated ssh-nonfree/ssh-socks packages for those users who have not yet migrated to OpenSSH. However, we do recommend that our users migrate to the regularly supported, DFSG-free "ssh" package as soon as possible. ssh 1.2.3-9.3 is the OpenSSH package available in Debian 2.2r4.

The fixed ssh-nonfree/ssh-socks packages are available in version 1.2.27-6.2 for use with Debian 2.2 (potato) and version 1.2.27-8 for use with the Debian unstable/testing distribution. Note that the new ssh-nonfree/ssh-socks packages remove the setuid bit from the ssh binary, disabling rhosts-rsa authentication. If you need this functionality, run

chmod u+s /usr/bin/ssh4

after installing the new package.

Fixed in:

Debian GNU/Linux 2.2 (potato)

Source:
http://security.debian.org/dists/potato/updates/non-free/source/ssh-nonfree_1.2.27-6.2.diff.gz
http://security.debian.org/dists/potato/updates/non-free/source/ssh-nonfree_1.2.27-6.2.dsc
http://security.debian.org/dists/potato/updates/non-free/source/ssh-nonfree_1.2.27.orig.tar.gz
Alpha:
http://security.debian.org/dists/potato/updates/non-free/binary-alpha/ssh-askpass-nonfree_1.2.27-6.2_alpha.deb
http://security.debian.org/dists/potato/updates/non-free/binary-alpha/ssh-nonfree_1.2.27-6.2_alpha.deb
http://security.debian.org/dists/potato/updates/non-free/binary-alpha/ssh-socks_1.2.27-6.2_alpha.deb
ARM: Not yet available
Intel ia32:
http://security.debian.org/dists/potato/updates/non-free/binary-i386/ssh-askpass-nonfree_1.2.27-6.2_i386.deb
http://security.debian.org/dists/potato/updates/non-free/binary-i386/ssh-nonfree_1.2.27-6.2_i386.deb
http://security.debian.org/dists/potato/updates/non-free/binary-i386/ssh-socks_1.2.27-6.2_i386.deb
Motorola M680x0:
http://security.debian.org/dists/potato/updates/non-free/binary-m68k/ssh-askpass-nonfree_1.2.27-6.2_m68k.deb
http://security.debian.org/dists/potato/updates/non-free/binary-m68k/ssh-nonfree_1.2.27-6.2_m68k.deb
http://security.debian.org/dists/potato/updates/non-free/binary-m68k/ssh-socks_1.2.27-6.2_m68k.deb
PowerPC:
http://security.debian.org/dists/potato/updates/non-free/binary-powerpc/ssh-askpass-nonfree_1.2.27-6.2_powerpc.deb
http://security.debian.org/dists/potato/updates/non-free/binary-powerpc/ssh-nonfree_1.2.27-6.2_powerpc.deb
http://security.debian.org/dists/potato/updates/non-free/binary-powerpc/ssh-socks_1.2.27-6.2_powerpc.deb
Sun Sparc:
http://security.debian.org/dists/potato/updates/non-free/binary-sparc/ssh-askpass-nonfree_1.2.27-6.2_sparc.deb
http://security.debian.org/dists/potato/updates/non-free/binary-sparc/ssh-nonfree_1.2.27-6.2_sparc.deb
http://security.debian.org/dists/potato/updates/non-free/binary-sparc/ssh-socks_1.2.27-6.2_sparc.deb

MD5 checksums of the listed files are available in the original advisory.