Earlier in the day today Red Hat made an announcement [1] that there had been an intrusion into some of their computer systems last week. In the same announcement they mention that some of the packages for OpenSSH on RHEL-4 ( i386 and x86_64 ) as well as RHEL-5 ( x86_64 ) were signed by the intruder. In their announcement they also clarified that they were confident that none of these, potentially compromised, packages made their way into or through RHN to client and customer machines. As a security measure a script [3] was made available along with a semi-detailed description of the issue [2].
We take security issues very seriously, and as soon as we were made aware of the situation I undertook a complete audit of the entire CentOS4/5 Build and Signing infrastructure. We can now assure everyone that no compromise has taken place anywhere within the CentOS Infrastructure. Our entire setup is located behind multiple firewalls, and only accessible from a very small number of places, by only a few people. Also included in this audit were all entry points to the build services, signing machines, primary release machines and connectivity between all these hosts.
Since OpenSSH is a critical component of any Linux machine, we considered it essential to audit the last two released package sets ( openssh-4.3p2-26.el5.src.rpm, openssh-4.3p2-26.el5_2.1.src.rpm ). I have just finished this code audit, and can assure everyone that there is no compromised code included in either of these packages. A similar check is also being done for the CentOS-4 sources.
Packages released today, by upstream, ( based on : openssh-4.3p2-26.el5_2.1.src.rpm, openssh-3.9p1-11.el4_7.src.rpm ) address two issues. Firstly they contain a fix for http://cve.mitre.org/cgi-bin/cvename.cgi?name=CVE-2007-4752 . And secondly, in the remote event that someone had indeed got compromised packages via RHN, their packages would get updated to a known good state. We wanted to get these packages out right away to address the first issue, and also to cover users converting non updated RHEL installs to CentOS in the next few weeks/months. Release of these packages into the mirror.centos.org network does *not* imply that CentOS users are affected by the intrusion at Red Hat.
Finally, while we feel confident that there is no possibility of this compromise having been passed onto the CentOS userbase, we still encourage users to verify their packages independently using whatever resources they might have available.
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[1]: https://rhn.redhat.com/errata/RHSA-2008-0855.html
[2]: http://www.redhat.com/security/data/openssh-blacklist.html
[3]: https://www.redhat.com/security/data/openssh-blacklist-1.0.sh :Its important to note that this script *only* checks for packages built within Red Hat, and will *not* be a reliable source of verification on CentOS since we rebuild from sources, using no Red Hat binary.