The WebKit Canvas implementation in Apple iOS before 9.3.2, Safari before 9.1.1, and tvOS before 9.2.1 allows remote attackers to execute arbitrary code or cause a denial of service (memory corruption) via a crafted web site.

A large number of security issues were discovered in the WebKitGTK+ Web and JavaScript engines. If a user were tricked into viewing a malicious website, a remote attacker could exploit a variety of issues related to web browser security, including cross-site scripting attacks, denial of service attacks, and arbitrary code execution.

Note that Tenable Network Security has extracted the preceding description block directly from the Ubuntu security advisory. Tenable has attempted to automatically clean and format it as much as possible without introducing additional issues.

The version of Safari installed on the remote host is prior or equal to 9.1, and is affected by multiple vulnerabilities. These vulnerablilities are contained within the Webkit subcomponent.

The remote host is running a version of iOS 9.3.x prior to version 9.3.2 and the following components contain vulnerabilities :

 - libxml2
 - WebKit

Versions of Apple TV 9.2.x earlier than 9.2.1 are vulnerable to the following issues :

 - 'Libxml2' contains an out-of-bounds read flaw in the 'xmlParseEndTag2()' function found within 'parser.c'. The vulnerability is triggered when parsing an end tag. This may allow a context-dependent attacker to crash a process linked against the library or potentially disclose memory contents. (CVE-2016-1838)
 - An out-of-bounds read flaw in the 'xmlNextChar()' function found within 'parserInternals.c' is triggered when parsing characters in an XML file. This may allow a context-dependent attacker to crash a process linked against the library or potentially disclose memory contents. (CVE-2016-1833)
 - An overflow condition exists within the 'htmlParseName()' and 'htmlParseNameComplex()' functions of 'HTMLparser.c'. The issue is triggered as user-supplied input is not properly validated when parsing characters in a range. With a specially crafted file, a context-dependent attacker can cause a heap-based buffer overflow, resulting in a denial of service or potentially allowing the execution of arbitrary code. (CVE-2016-1839)
 - A use-after-free error is triggered when handling 'GraphicsContext' objects in memory. With a specially crafted web page, a context-dependent attacker can dereference already freed memory and execute arbitrary code. (CVE-2016-1859)
 - A use-after-free error is triggered when handling 'TextTrack' objects in memory. With a specially crafted web page, a context-dependent attacker can dereference already freed memory and execute arbitrary code. (CVE-2016-1856)
 - A use-after-free condition is triggered as user-supplied input is not properly validated when handling 'ArrayStorage DFG' optimization. With a specially crafted web page, a context-dependent attacker can dereference already freed memory and execute arbitrary code. (CVE-2016-1857)

Versions of Apple TV earlier than 9.2.1 are unpatched for vulnerabilities in the following components :

 - CFNetwork Proxies
 - CommonCrypto
 - CoreCapture
 - Disk Images
 - ImageIO
 - IOAcceleratorFamily
 - IOHIDFamily
 - Kernel
 - libc
 - libxml2
 - libxslt
 - OpenGL
 - WebKit
 - WebKit Canvas
 

The remote host is running a version of iOS that is prior to version 9.3.2 and the following components contain vulnerabilities :

 - Accessibility
 - CFNetwork Proxies
 - CommonCrypto
 - CoreCapture
 - Disk Images
 - ImageIO
 - IOAcceleratorFamily
 - IOHIDFamily
 - Kernel
 - libc
 - libxml2
 - libxslt
 - MapKit
 - OpenGL
 - Safari
 - Siri
 - WebKit
 - WebKit Canvas

According to its banner, the version of the remote Apple TV device is prior to 9.2.1. It is, therefore, affected by multiple vulnerabilities in the following components :

  - CFNetwork Proxies
  - CommonCrypto
  - CoreCapture
  - Disk Images
  - ImageIO
  - IOAcceleratorFamily
  - IOHIDFamily
  - Kernel
  - libc
  - libxml2
  - libxslt
  - OpenGL
  - WebKit
  - WebKit Canvas

Note that only 4th generation models are affected by the vulnerabilities.

The mobile device is running a version of iOS prior to 9.3.2. It is, therefore, affected by multiple vulnerabilities in the following components :

  - Accessibility
  - CFNetwork Proxies
  - CommonCrypto
  - CoreCapture
  - Disk Images
  - ImageIO
  - IOAcceleratorFamily
  - IOHIDFamily
  - Kernel
  - libc
  - libxml2
  - libxslt
  - MapKit
  - OpenGL
  - Safari
  - Siri
  - WebKit
  - WebKit Canvas

The version of Apple Safari installed on the remote Mac OS X host is prior to 9.1.1. It is, therefore, affected by the following vulnerabilities :

  - An information disclosure vulnerability exists due to a     failure to completely delete a user's browser history     when using the 'Clear History and Website Data' action.
    An attacker can exploit this to disclose sensitive     information. (CVE-2016-1849)

  - Multiple memory corruption issues exist in WebKit due to     improper validation of user-supplied input. A remote     attacker, via a specially crafted website, can exploit     these issues to execute arbitrary code. (CVE-2016-1854,     CVE-2016-1855, CVE-2016-1856, CVE-2016-1857,     CVE-2016-1859)

  - An information disclosure vulnerability exists in WebKit     due to insufficient taint tracking. A remote attacker     can exploit this, via a specially crafted SVG image, to     disclose information from another website.
    (CVE-2016-1858)

ID	Name	Product	Family	Severity
93511	Ubuntu 16.04 LTS : WebKitGTK+ vulnerabilities (USN-3079-1)	Nessus	Ubuntu Local Security Checks	high
9549	Safari < 9.1.1 Multiple Vulnerabilities	Nessus Network Monitor	Web Clients	medium
9444	Apple iOS 9.3.x < 9.3.2 Multiple Vulnerabilities	Nessus Network Monitor	Mobile Devices	medium
9431	Apple TV 9.2.x < 9.2.1 Multiple Vulnerabilities	Nessus Network Monitor	Internet Services	medium
9337	Apple TV < 9.2.1 Multiple Vulnerabilities	Nessus Network Monitor	Internet Services	high
9332	Apple iOS < 9.3.2 Multiple Vulnerabilities	Nessus Network Monitor	Mobile Devices	high
91311	Apple TV < 9.2.1 Multiple Vulnerabilities	Nessus	Misc.	high
91225	Apple iOS < 9.3.2 Multiple Vulnerabilities	Nessus	Mobile Devices	high
91221	Mac OS X : Apple Safari < 9.1.1 Multiple Vulnerabilities	Nessus	MacOS X Local Security Checks	high

Detections

Analytics

CVE-2016-1859

high

Tenable Plugins

high

medium

medium

medium

high

high

high

high

high