USN-2994-1: libxml2 vulnerabilities

Ubuntu Security Notice USN-2994-1

6th June, 2016

libxml2 vulnerabilities

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

• Ubuntu 16.04 LTS
• Ubuntu 15.10
• Ubuntu 14.04 LTS
• Ubuntu 12.04 LTS

Summary

Several security issues were fixed in libxml2.

Software description

• libxml2 - GNOME XML library

Details

It was discovered that libxml2 incorrectly handled certain malformed
documents. If a user or automated system were tricked into opening a
specially crafted document, an attacker could possibly cause libxml2 to
crash, resulting in a denial of service. (CVE-2015-8806, CVE-2016-2073,
CVE-2016-3627, CVE-2016-3705, CVE-2016-4447)

It was discovered that libxml2 incorrectly handled certain malformed
documents. If a user or automated system were tricked into opening a
specially crafted document, an attacker could cause libxml2 to crash,
resulting in a denial of service, or possibly execute arbitrary code.
(CVE-2016-1762, CVE-2016-1834)

Mateusz Jurczyk discovered that libxml2 incorrectly handled certain
malformed documents. If a user or automated system were tricked into
opening a specially crafted document, an attacker could cause libxml2 to
crash, resulting in a denial of service, or possibly execute arbitrary
code. (CVE-2016-1833, CVE-2016-1838, CVE-2016-1839)

Wei Lei and Liu Yang discovered that libxml2 incorrectly handled certain
malformed documents. If a user or automated system were tricked into
opening a specially crafted document, an attacker could cause libxml2 to
crash, resulting in a denial of service, or possibly execute arbitrary
code. (CVE-2016-1835, CVE-2016-1837)

Wei Lei and Liu Yang discovered that libxml2 incorrectly handled certain
malformed documents. If a user or automated system were tricked into
opening a specially crafted document, an attacker could cause libxml2 to
crash, resulting in a denial of service, or possibly execute arbitrary
code. This issue only applied to Ubuntu 14.04 LTS, Ubuntu 15.10 and
Ubuntu 16.04 LTS. (CVE-2016-1836)

Kostya Serebryany discovered that libxml2 incorrectly handled certain
malformed documents. If a user or automated system were tricked into
opening a specially crafted document, an attacker could cause libxml2 to
crash, resulting in a denial of service, or possibly execute arbitrary
code. (CVE-2016-1840)

It was discovered that libxml2 would load certain XML external entities. If
a user or automated system were tricked into opening a specially crafted
document, an attacker could possibly obtain access to arbitrary files or
cause resource consumption. (CVE-2016-4449)

Gustavo Grieco discovered that libxml2 incorrectly handled certain
malformed documents. If a user or automated system were tricked into
opening a specially crafted document, an attacker could possibly cause
libxml2 to crash, resulting in a denial of service. (CVE-2016-4483)

Update instructions

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

Ubuntu 16.04 LTS:

libxml2 2.9.3+dfsg1-1ubuntu0.1

Ubuntu 15.10:

libxml2 2.9.2+zdfsg1-4ubuntu0.4

Ubuntu 14.04 LTS:

libxml2 2.9.1+dfsg1-3ubuntu4.8

Ubuntu 12.04 LTS:

libxml2 2.7.8.dfsg-5.1ubuntu4.15

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

After a standard system update you need to reboot your computer to make
all the necessary changes.

References

CVE-2015-8806, CVE-2016-1762, CVE-2016-1833, CVE-2016-1834, CVE-2016-1835, CVE-2016-1836, CVE-2016-1837, CVE-2016-1838, CVE-2016-1839, CVE-2016-1840, CVE-2016-2073, CVE-2016-3627, CVE-2016-3705, CVE-2016-4447, CVE-2016-4449, CVE-2016-4483