Barrapunto

Leo en bugtraq que uno de los servidores de rsync de Gentoo ha sido comprometido por un atacante. Al parecer, el atacante instaló un rootkit en el servidor y trató de ocultar su actividad en el sistema, pero no llegó a modificar nada del árbol de portage. El servidor estuvo aproximadamente una hora comprometido, tiempo tras el cual fue apagado y retirado de línea. Unos 20 usuarios actualizaron su árbol de portage desde ese servidor en ese tiempo. Se recomienda a los paranoicos con la seguridad que actualicen de nuevo con emerge sync.

GLSA: 200312-01
summary: rsync.gentoo.org rotation server compromised
severity: normal
date: 2003-12-02
CVE: None
exploit: remote

DESCRIPTION:

On December 2nd at approximately 03:45 UTC, one of the servers that makes up the rsync.gentoo.org rotation was compromised via a remote exploit. At this point, we are still performing forensic analysis. However, the compromised system had both an IDS and a file integrity checker installed and we have a very detailed forensic trail of what happened once the box was breached, so weare reasonably confident that the portage tree stored on that box wasunaffected.

The attacker appears to have installed a rootkit and modified/deleted some files to cover their tracks, but left the server otherwise untouched. The box was in a compromised state for approximately one hour before it was discovered and shut down. During this time, approximately 20 users synchronized against the portage mirror stored on this box. The method used to gain access to the box remotely is still under investigation.We will release more details once we have ascertained the cause of the remote exploit.

This box is not an official Gentoo infrastructure box and is instead donated by a sponsor. The box provides other services as well and the sponsor has requested that we not publicly identify the box at this time. Because the Gentoo part of this box appears to be unaffected by this exploit, we are currently honoring the sponsor's request. That said, if at any point, we determine that any file in the portage tree was modified in any way, we will release full details about the compromised server.

SOLUTION:

Again, based on the forensic analysis done so far, we are reasonably confident that no files within the Portage tree on the box were affected. However, the server has been removed from all rsync.*.gentoo.org rotations and will remain so until the forensic analysis has been completed and the box has been wiped and rebuilt. Thus, users preferring an extra level of security may ensure that they have a correct and accurate portage tree by running:

emerge sync

Which will perform a sync against another server and ensure that all files are up to date.