USN-1188-1: eCryptfs vulnerabilities

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)