4.35. ecryptfs-utils

Updated ecryptfs-utils packages that fix several security issues are now available for Red Hat Enterprise Linux 5 and 6.
The Red Hat Security Response Team has rated this update as having moderate security impact. Common Vulnerability Scoring System (CVSS) base scores, which give detailed severity ratings, are available for each vulnerability from the CVE links associated with each description below.
eCryptfs is a stacked, cryptographic file system. It is transparent to the underlying file system and provides per-file granularity. eCryptfs is released as a Technology Preview for Red Hat Enterprise Linux 5 and 6.

Security Fixes

CVE-2011-1831
The setuid mount.ecryptfs_private utility allows users to mount an eCryptfs file system. This utility can only be run by users in the "ecryptfs" group.
A race condition flaw was found in the way mount.ecryptfs_private checked the permissions of a requested mount point when mounting an encrypted file system. A local attacker could possibly use this flaw to escalate their privileges by mounting over an arbitrary directory.
CVE-2011-1832
A race condition flaw in umount.ecryptfs_private could allow a local attacker to unmount an arbitrary file system.
CVE-2011-1834
It was found that mount.ecryptfs_private did not handle certain errors correctly when updating the mtab (mounted file systems table) file, allowing a local attacker to corrupt the mtab file and possibly unmount an arbitrary file system.
CVE-2011-1835
An insecure temporary file use flaw was found in the ecryptfs-setup-private script. A local attacker could use this script to insert their own key that will subsequently be used by a new user, possibly giving the attacker access to the user's encrypted data if existing file permissions allow access.
CVE-2011-1837
A race condition flaw in mount.ecryptfs_private could allow a local attacker to overwrite arbitrary files.
CVE-2011-3145
A race condition flaw in the way temporary files were accessed in mount.ecryptfs_private could allow a malicious, local user to make arbitrary modifications to the mtab file.
CVE-2011-1833
A race condition flaw was found in the way mount.ecryptfs_private checked the permissions of the directory to mount. A local attacker could use this flaw to mount (and then access) a directory they would otherwise not have access to. Note: The fix for this issue is incomplete until a kernel-space change is made. Future Red Hat Enterprise Linux 5 and 6 kernel updates will correct this issue.
Red Hat would like to thank the Ubuntu Security Team for reporting these issues. The Ubuntu Security Team acknowledges Vasiliy Kulikov of Openwall and Dan Rosenberg as the original reporters of CVE-2011-1831, CVE-2011-1832, and CVE-2011-1833; Dan Rosenberg and Marc Deslauriers as the original reporters of CVE-2011-1834; Marc Deslauriers as the original reporter of CVE-2011-1835; and Vasiliy Kulikov of Openwall as the original reporter of CVE-2011-1837.
Users of ecryptfs-utils are advised to upgrade to these updated packages, which contain backported patches to correct these issues.
Updated ecryptfs-utils packages that fix several bugs are now available for Red Hat Enterprise Linux 5.
eCryptfs is a stacked, cryptographic file system. It is transparent to the underlying file system and provides per-file granularity.
eCryptfs is released as a Technology Preview for Red Hat Enterprise Linux 5.8.

Bug Fixes

BZ#554740
Previously, the eCryptfs daemon, ecryptfsd, failed to start if the ecryptfs kernel module had not already created the files necessary for user space communication under the /dev/ and /dev/misc/ directories, and "No such file or directory" messages were logged. This update avoids this race condition by ensuring that the ecryptfsd daemon waits and then attempts to start again if it discovers that the requisite files have not yet been created.
BZ#553629
Prior to this update ecryptfs did not correctly handle the salt option together with the password file. As a result mounting of the encrypted file system would fail and the error, "Bad address", would be displayed. With this update ecryptfs correctly handles the salt option and mounting of the encrypted file system using eCryptfs no longer fails.
All users of ecryptfs-utils are advised to upgrade to these updated packages, which fix these bugs.