Red Hat Bugzilla – Full Text Bug Listing
|Summary:||CVE-2012-3409 ecryptfs-utils: suid helper does not restrict mounting filesystems with nosuid,nodev leading to possible privilege escalation|
|Product:||[Other] Security Response||Reporter:||Vincent Danen <vdanen>|
|Component:||vulnerability||Assignee:||Red Hat Product Security <security-response-team>|
|Status:||CLOSED ERRATA||QA Contact:|
|Fixed In Version:||Doc Type:||Bug Fix|
|Doc Text:||Story Points:||---|
|Last Closed:||2012-07-24 00:54:33 EDT||Type:||---|
|oVirt Team:||---||RHEL 7.3 requirements from Atomic Host:|
|Bug Depends On:||842512|
Description Vincent Danen 2012-07-20 11:25:56 EDT
It was reported  that the private ecryptfs mount helper (/sbin/mount.ecryptfs_private), which is setuid-root, could allow an unprivileged local user to mount user-controlled ecryptfs shares on the local system. Because the ecryptfs helper does not mount filesystems with the "nosuid" and "nodev" flags, it would be possible for a user to mount a filesystem containing setuid-root binaries and/or device files that could lead to the escalation of their privileges. This could be done via a USB device, if the user had physical access to the system. It was however also noted  that this may only affect version 86 and later, as the encrypted home source and destination mount points were hard-coded up until that version. Forcing MS_NOSUID and MS_NODEV mount flags was added to version 99 (commits ,)  http://www.openwall.com/lists/oss-security/2012/07/10/19  http://www.openwall.com/lists/oss-security/2012/07/11/2  http://bazaar.launchpad.net/~ecryptfs/ecryptfs/trunk/revision/705  http://bazaar.launchpad.net/~ecryptfs/ecryptfs/trunk/revision/708
Comment 1 Vincent Danen 2012-07-20 11:30:39 EDT
I also forgot to note that on Fedora and RHEL, you need to be part of the ecryptfs group to even use the ecryptfs filesystems/utilities, which lowers the attack surface considerably.
Comment 3 Huzaifa S. Sidhpurwala 2012-07-24 00:53:07 EDT
Statement: Not Vulnerable. This issue does not affect the version of ecryptfs-utils as shipped with Red Hat Enterprise Linux 5 and 6.
Comment 4 Huzaifa S. Sidhpurwala 2012-07-24 00:53:57 EDT
Created ecryptfs-utils tracking bugs for this issue Affects: fedora-all [bug 842512]
Comment 5 Fedora Update System 2012-08-03 07:27:42 EDT
ecryptfs-utils-99-1.fc17 has been pushed to the Fedora 17 stable repository. If problems still persist, please make note of it in this bug report.
Comment 6 Fedora Update System 2012-08-03 07:28:20 EDT
ecryptfs-utils-99-1.fc16 has been pushed to the Fedora 16 stable repository. If problems still persist, please make note of it in this bug report.