USN-1188-1: eCryptfs vulnerabilities
9 August 2011
eCryptfs could be tricked into mounting and unmounting arbitrary locations, and possibly disclose confidential information.
Releases
Packages
- ecryptfs-utils - ecryptfs cryptographic filesystem (utilities)
Details
Vasiliy Kulikov and Dan Rosenberg discovered that eCryptfs incorrectly
validated permissions on the requested mountpoint. A local attacker could
use this flaw to mount to arbitrary locations, leading to privilege
escalation. (CVE-2011-1831)
Vasiliy Kulikov and Dan Rosenberg discovered that eCryptfs incorrectly
validated permissions on the requested mountpoint. A local attacker could
use this flaw to unmount to arbitrary locations, leading to a denial of
service. (CVE-2011-1832)
Vasiliy Kulikov and Dan Rosenberg discovered that eCryptfs incorrectly
validated permissions on the requested source directory. A local attacker
could use this flaw to mount an arbitrary directory, possibly leading to
information disclosure. A pending kernel update will provide the other
half of the fix for this issue. (CVE-2011-1833)
Dan Rosenberg and Marc Deslauriers discovered that eCryptfs incorrectly
handled modifications to the mtab file when an error occurs. A local
attacker could use this flaw to corrupt the mtab file, and possibly unmount
arbitrary locations, leading to a denial of service. (CVE-2011-1834)
Marc Deslauriers discovered that eCryptfs incorrectly handled keys when
setting up an encrypted private directory. A local attacker could use this
flaw to manipulate keys during creation of a new user. (CVE-2011-1835)
Marc Deslauriers discovered that eCryptfs incorrectly handled permissions
during recovery. A local attacker could use this flaw to possibly access
another user's data during the recovery process. This issue only applied to
Ubuntu 11.04. (CVE-2011-1836)
Vasiliy Kulikov discovered that eCryptfs incorrectly handled lock counters.
A local attacker could use this flaw to possibly overwrite arbitrary files.
The default symlink restrictions in Ubuntu 10.10 and 11.04 should protect
against this issue. (CVE-2011-1837)
Update instructions
The problem can be corrected by updating your system to the following package versions:
Ubuntu 11.04
Ubuntu 10.10
Ubuntu 10.04
In general, a standard system update will make all the necessary changes.