USN-1288-1

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

- Ubuntu 11.10
- Ubuntu 11.04
- Ubuntu 10.10
- Ubuntu 10.04 LTS

Summary:

Vsftpd or other applications could be made to crash if vsftpd received
specially crafted network traffic.

Software Description:
- vsftpd: FTP server written for security

Details:

It was discovered that the 2.6.35 and earlier Linux kernel does not
properly handle a high rate of creation and cleanup of network namespaces,
which makes it easier for remote attackers to cause a denial of service
(memory consumption) in applications that require a separate namespace per
connection, like vsftpd. This update adjusts vsftpd to only use network
namespaces on kernels that are known to be not affected.

Update instructions:

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

Ubuntu 11.10:
vsftpd 2.3.2-3ubuntu5.1

Ubuntu 11.04:
vsftpd 2.3.2-3ubuntu4.1

Ubuntu 10.10:
vsftpd 2.3.0~pre2-4ubuntu2.3

Ubuntu 10.04 LTS:
vsftpd 2.2.2-3ubuntu6.3

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

References:
http://www.ubuntu.com/usn/usn-1288-1
CVE-2011-2189

Package Information:
https://launchpad.net/ubuntu/+source/vsftpd/2.3.2-3ubuntu5.1
https://launchpad.net/ubuntu/+source/vsftpd/2.3.2-3ubuntu4.1
https://launchpad.net/ubuntu/+source/vsftpd/2.3.0~pre2-4ubuntu2.3
https://launchpad.net/ubuntu/+source/vsftpd/2.2.2-3ubuntu6.3