USN-1196-1: eCryptfs vulnerability

Ubuntu Security Notice USN-1196-1

23rd August, 2011

ecryptfs-utils vulnerability

A security issue affects these releases of Ubuntu and its derivatives:

  • Ubuntu 11.04
  • Ubuntu 10.10
  • Ubuntu 10.04 LTS

Summary

An attacker could use eCryptfs to unmount arbitrary locations and cause a denial of service.

Software description

  • ecryptfs-utils - ecryptfs cryptographic filesystem (utilities)

Details

It was discovered that eCryptfs incorrectly handled permissions when
modifying the mtab file. A local attacker could use this flaw to manipulate
the mtab file, and possibly unmount arbitrary locations, leading to a
denial of service.

Update instructions

The problem can be corrected by updating your system to the following package version:

Ubuntu 11.04:
ecryptfs-utils 87-0ubuntu1.2
Ubuntu 10.10:
ecryptfs-utils 83-0ubuntu3.2.10.10.2
Ubuntu 10.04 LTS:
ecryptfs-utils 83-0ubuntu3.2.10.04.2

To update your system, please follow these instructions: https://wiki.ubuntu.com/Security/Upgrades.

In general, a standard system update will make all the necessary changes.

References

CVE-2011-3145