Ubuntu Tutorials

The following security announcement applies to smbfs. If you have smbfs installed, please see below for details on the vulnerability and instructions on patching your system:

Ronald Volgers discovered that the mount.cifs utility, when installed as a
setuid program, suffered from a race condition when verifying user
permissions. A local attacker could trick samba into mounting over
arbitrary locations, leading to a root privilege escalation.

The above security vulnerabilities apply to the following Ubuntu releases:

• Ubuntu 6.06 LTS
• Ubuntu 8.04 LTS
• Ubuntu 8.10
• Ubuntu 9.04
• Ubuntu 9.10

If you are have this utility installed on your Ubuntu system you’ll need to apply the security update to be protected. Please follow the steps below to ensure your system is properly patched:

Apply Updates

To apply the updates run the following command(s) within your Terminal:

sudo aptitude update
sudo aptitude safe-upgrade

In general, a standard system upgrade is sufficient to effect the necessary changes.

The following security announcement applies to lintian. If you have lintian installed, please see below for details on the vulnerability and instructions on patching your system:

It was discovered that lintian did not correctly validate certain
filenames when processing input.  If a user or an automated system
were tricked into running lintian on a specially crafted set of files,
a remote attacker could execute arbitrary code with user privileges.

The above security vulnerabilities apply to the following Ubuntu releases:

• Ubuntu 6.06 LTS
• Ubuntu 8.04 LTS
• Ubuntu 8.10
• Ubuntu 9.04
• Ubuntu 9.10

If you are have this utility installed on your Ubuntu system you’ll need to apply the security update to be protected. Please follow the steps below to ensure your system is properly patched:

Apply Updates

To apply the updates run the following command(s) within your Terminal:

sudo aptitude update
sudo aptitude safe-upgrade

In general, a standard system upgrade is sufficient to effect the necessary changes.

The following security announcement applies to dhcp-client. If you have dhcp-client installed, please see below for details on the vulnerability and instructions on patching your system:

USN-803-1 fixed a vulnerability in Dhcp. Due to an error, the patch to
fix the vulnerability was not properly applied on Ubuntu 8.10 and higher.
Even with the patch improperly applied, the default compiler options
reduced the vulnerability to a denial of service. Additionally, in Ubuntu
9.04 and higher, users were also protected by the AppArmor dhclient3
profile. This update fixes the problem.

Original advisory details:

It was discovered that the DHCP client as included in dhcp3 did not verify
the length of certain option fields when processing a response from an IPv4
dhcp server. If a user running Ubuntu 6.06 LTS or 8.04 LTS connected to a
malicious dhcp server, a remote attacker could cause a denial of service or
execute arbitrary code as the user invoking the program, typically the
‘dhcp’ user. For users running Ubuntu 8.10 or 9.04, a remote attacker
should only be able to cause a denial of service in the DHCP client. In
Ubuntu 9.04, attackers would also be isolated by the AppArmor dhclient3
profile.

The above security vulnerabilities apply to the following Ubuntu releases:

• Ubuntu 8.10
• Ubuntu 9.04
• Ubuntu 9.10

If you are have this utility installed on your Ubuntu system you’ll need to apply the security update to be protected. Please follow the steps below to ensure your system is properly patched:

Apply Updates

To apply the updates run the following command(s) within your Terminal:

sudo aptitude update
sudo aptitude safe-upgrade

After a standard system upgrade you need to restart any DHCP network connections utilizing dhclient3 to effect the necessary changes.

The following security announcement applies to Python. If you have Python installed, please see below for details on the vulnerability and instructions on patching your system:

USN-890-1 fixed vulnerabilities in Expat. This update provides the
corresponding updates for PyXML.

Original advisory details:

Jukka Taimisto, Tero Rontti and Rauli Kaksonen discovered that Expat did
not properly process malformed XML. If a user or application linked against
Expat were tricked into opening a crafted XML file, an attacker could cause
a denial of service via application crash. (CVE-2009-2625, CVE-2009-3720)

It was discovered that Expat did not properly process malformed UTF-8
sequences. If a user or application linked against Expat were tricked into
opening a crafted XML file, an attacker could cause a denial of service via
application crash. (CVE-2009-3560)

The above security vulnerabilities apply to the following Ubuntu releases:

• Ubuntu 6.06 LTS

If you are have this utility installed on your Ubuntu system you’ll need to apply the security update to be protected. Please follow the steps below to ensure your system is properly patched:

Apply Updates

To apply the updates run the following command(s) within your Terminal:

sudo aptitude update
sudo aptitude safe-upgrade

After a standard system upgrade you need to restart any applications that use PyXML to effect the necessary changes.

The following security announcement applies to Python. If you have Python installed, please see below for details on the vulnerability and instructions on patching your system:

USN-890-1 fixed vulnerabilities in Expat. This update provides the
corresponding updates for the PyExpat module in Python 2.5.

Original advisory details:

Jukka Taimisto, Tero Rontti and Rauli Kaksonen discovered that Expat did
not properly process malformed XML. If a user or application linked against
Expat were tricked into opening a crafted XML file, an attacker could cause
a denial of service via application crash. (CVE-2009-2625, CVE-2009-3720)

It was discovered that Expat did not properly process malformed UTF-8
sequences. If a user or application linked against Expat were tricked into
opening a crafted XML file, an attacker could cause a denial of service via
application crash. (CVE-2009-3560).

The above security vulnerabilities apply to the following Ubuntu releases:

• Ubuntu 8.04 LTS
• Ubuntu 8.10
• Ubuntu 9.04
• Ubuntu 9.10

If you are have this utility installed on your Ubuntu system you’ll need to apply the security update to be protected. Please follow the steps below to ensure your system is properly patched:

Apply Updates

To apply the updates run the following command(s) within your Terminal:

sudo aptitude update
sudo aptitude safe-upgrade

After a standard system upgrade you need to restart any Python applications that use the PyExpat module to effect the necessary changes.

The following security announcement applies to Expat. If you have Expat installed, please see below for details on the vulnerability and instructions on patching your system:

Jukka Taimisto, Tero Rontti and Rauli Kaksonen discovered that Expat did
not properly process malformed XML. If a user or application linked against
Expat were tricked into opening a crafted XML file, an attacker could cause
a denial of service via application crash. (CVE-2009-2625, CVE-2009-3720)

It was discovered that Expat did not properly process malformed UTF-8
sequences. If a user or application linked against Expat were tricked into
opening a crafted XML file, an attacker could cause a denial of service via
application crash. (CVE-2009-3560).

The above security vulnerabilities apply to the following Ubuntu releases:

• Ubuntu 6.06 LTS
• Ubuntu 8.04 LTS
• Ubuntu 8.10
• Ubuntu 9.04
• Ubuntu 9.10

If you are have this utility installed on your Ubuntu system you’ll need to apply the security update to be protected. Please follow the steps below to ensure your system is properly patched:

Apply Updates

To apply the updates run the following command(s) within your Terminal:

sudo aptitude update
sudo aptitude safe-upgrade

In general, a standard system upgrade is sufficient to effect the necessary changes.

The following security announcement applies to gzip. If you have gzip installed on your system please see below for details on the vulnerability and instructions on patching your system:

It was discovered that gzip incorrectly handled certain malformed
compressed files. If a user or automated system were tricked into opening a
specially crafted gzip file, an attacker could cause gzip to crash or
possibly execute arbitrary code with the privileges of the user invoking
the program. (CVE-2009-2624)

Aki Helin discovered that gzip incorrectly handled certain malformed
files compressed with the Lempel–Ziv–Welch (LZW) algorithm. If a user or
automated system were tricked into opening a specially crafted gzip file,
an attacker could cause gzip to crash or possibly execute arbitrary code
with the privileges of the user invoking the program. (CVE-2010-0001).

The above security vulnerabilities apply to the following Ubuntu releases:

• Ubuntu 6.06 LTS
• Ubuntu 8.04 LTS
• Ubuntu 8.10
• Ubuntu 9.04
• Ubuntu 9.10

If you are have this utility installed on your Ubuntu system you’ll need to apply the security update to be protected. Please follow the steps below to ensure your system is properly patched:

Apply Updates

To apply the updates run the following command(s) within your Terminal:

sudo aptitude update
sudo aptitude safe-upgrade

In general, a standard system upgrade is sufficient to effect the necessary changes.

The following security announcement applies to BIND. If you have BIND installed on your system please see below for information about the vulnerability and instructions on patching your system:

It was discovered that Bind would incorrectly cache bogus NXDOMAIN
responses. When DNSSEC validation is in use, a remote attacker could
exploit this to cause a denial of service, and possibly poison DNS caches.
(CVE-2010-0097)

USN-865-1 provided updated Bind packages to fix a security vulnerability.
The upstream security patch to fix CVE-2009-4022 was incomplete and
CVE-2010-0290 was assigned to the issue. This update corrects the problem.
Original advisory details:

Michael Sinatra discovered that Bind did not correctly validate certain
records added to its cache. When DNSSEC validation is in use, a remote
attacker could exploit this to spoof DNS entries and poison DNS caches.
Among other things, this could lead to misdirected email and web traffic.

The above security vulnerabilities apply to the following Ubuntu releases:

• Ubuntu 6.06 LTS
• Ubuntu 8.04 LTS
• Ubuntu 8.10
• Ubuntu 9.04
• Ubuntu 9.10

If you are running BIND on Ubuntu you’ll need to apply the security update to be protected. Please follow the steps below to ensure your system is properly patched:

Apply Updates

To apply the updates run the following command(s) within your Terminal:

sudo aptitude update
sudo aptitude safe-upgrade

In general, a standard system upgrade is sufficient to effect the necessary changes.

We’ve got one more security vulnerability to announce this morning. This one likely does not affect as many users, but it should require attention nonetheless.

Detail follow:

• Tim Starling discovered that LibThai did not correctly handle long strings. A remote attacker could use specially-formed strings to execute arbitrary code with the user’s privileges.

You can apply this patch using the graphical Update Manager utility, or by running the following two commands from the Terminal:

sudo aptitude update

sudo aptitude safe-upgrade

In general, a standard system upgrade is sufficient to effect the necessary changes.

We’ve got a load of security vulnerabilities to announce for Pidgin today. The patched packages should be available for download at most Ubuntu mirrors. I would advise that you update as soon as possible.

Details follow:

• It was discovered that Pidgin did not properly handle certain topic messages in the IRC protocol handler. If a user were tricked into connecting to a malicious IRC server, an attacker could cause Pidgin to crash, leading to a denial of service. This issue only affected Ubuntu 8.04 LTS, Ubuntu 8.10 and Ubuntu 9.04. (CVE-2009-2703)
• It was discovered that Pidgin did not properly enforce the “require TLS/SSL” setting when connecting to certain older Jabber servers. If a remote attacker were able to perform a man-in-the-middle attack, this flaw could be exploited to view sensitive information. This issue only affected Ubuntu 8.04 LTS, Ubuntu 8.10 and Ubuntu 9.04. (CVE-2009-3026)
• It was discovered that Pidgin did not properly handle certain SLP invite messages in the MSN protocol handler. A remote attacker could send a specially crafted invite message and cause Pidgin to crash, leading to a denial of service. This issue only affected Ubuntu 8.04 LTS, Ubuntu 8.10 and Ubuntu 9.04. (CVE-2009-3083)
• It was discovered that Pidgin did not properly handle certain errors in the XMPP protocol handler. A remote attacker could send a specially crafted message and cause Pidgin to crash, leading to a denial of service. This issue only affected Ubuntu 8.10 and Ubuntu 9.04. (CVE-2009-3085)
• It was discovered that Pidgin did not properly handle malformed contact-list data in the OSCAR protocol handler. A remote attacker could send specially crafted contact-list data and cause Pidgin to crash, leading to a denial of service. (CVE-2009-3615)
• It was discovered that Pidgin did not properly handle custom smiley requests in the MSN protocol handler. A remote attacker could send a specially crafted filename in a custom smiley request and obtain arbitrary files via directory traversal. This issue only affected Ubuntu 8.10, Ubuntu 9.04 and Ubuntu 9.10. (CVE-2010-0013)

Pidgin for Ubuntu 8.04 LTS was also updated to fix connection issues with the MSN protocol.

USN-675-1 and USN-781-1 provided updated Pidgin packages to fix multiple security vulnerabilities in Ubuntu 8.04 LTS. The security patches to fix CVE-2008-2955 and CVE-2009-1376 were incomplete. This update corrects the problem.

Original advisory details:

• It was discovered that Pidgin did not properly handle file transfers containing a long filename and special characters in the MSN protocol handler. A remote attacker could send a specially crafted filename in a file transfer request and cause Pidgin to crash, leading to a denial of service. (CVE-2008-2955)
• It was discovered that Pidgin did not properly handle certain malformed messages in the MSN protocol handler. A remote attacker could send a specially crafted message and possibly execute arbitrary code with user privileges. (CVE-2009-1376)

To apply these fixes, please update your system as soon as possible. You can use the graphical Update Manager tool, or use the following two commands from the Terminal:

sudo aptitude update
sudo aptitude safe-upgrade


After a standard system upgrade you need to restart Pidgin to effect the necessary changes.