=========================================================================Ubuntu Security Notice USN-3424-1
September 19, 2017

libxml2 vulnerabilities
=========================================================================
A security issue affects these releases of Ubuntu and its derivatives:

- Ubuntu 17.04
- Ubuntu 16.04 LTS
- Ubuntu 14.04 LTS

Summary:

Several security issues were fixed in libxml2.

Software Description:
- libxml2: GNOME XML library

Details:

It was discovered that a type confusion error existed in libxml2. An
attacker could use this to specially construct XML data that
could cause a denial of service or possibly execute arbitrary
code. (CVE-2017-0663)

It was discovered that libxml2 did not properly validate parsed entity
references. An attacker could use this to specially construct XML
data that could expose sensitive information. (CVE-2017-7375)

It was discovered that a buffer overflow existed in libxml2 when
handling HTTP redirects. An attacker could use this to specially
construct XML data that could cause a denial of service or possibly
execute arbitrary code. (CVE-2017-7376)

Marcel Böhme and Van-Thuan Pham discovered a buffer overflow in
libxml2 when handling elements. An attacker could use this to specially
construct XML data that could cause a denial of service or possibly
execute arbitrary code. (CVE-2017-9047)

Marcel Böhme and Van-Thuan Pham discovered a buffer overread
in libxml2 when handling elements. An attacker could use this
to specially construct XML data that could cause a denial of
service. (CVE-2017-9048)

Marcel Böhme and Van-Thuan Pham discovered multiple buffer overreads
in libxml2 when handling parameter-entity references. An attacker
could use these to specially construct XML data that could cause a
denial of service. (CVE-2017-9049, CVE-2017-9050)

Update instructions:

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

Ubuntu 17.04:
  libxml2                         2.9.4+dfsg1-2.2ubuntu0.1

Ubuntu 16.04 LTS:
  libxml2                         2.9.3+dfsg1-1ubuntu0.3

Ubuntu 14.04 LTS:
  libxml2                         2.9.1+dfsg1-3ubuntu4.10

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

References:
  https://ubuntu.com/security/notices/USN-3424-1
  CVE-2017-0663, CVE-2017-7375, CVE-2017-7376, CVE-2017-9047,
  CVE-2017-9048, CVE-2017-9049, CVE-2017-9050

Package Information:
  https://launchpad.net/ubuntu/+source/libxml2/2.9.4+dfsg1-2.2ubuntu0.1
  https://launchpad.net/ubuntu/+source/libxml2/2.9.3+dfsg1-1ubuntu0.3
  https://launchpad.net/ubuntu/+source/libxml2/2.9.1+dfsg1-3ubuntu4.10