Apple Safari up to 9.1.1 WebKit User access control

CVSS Meta Temp Score
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CTI Interest Score
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A vulnerability, which was classified as critical, has been found in Apple Safari up to 9.1.1 (Web Browser). Affected by this issue is an unknown functionality of the component WebKit. The manipulation with an unknown input leads to a access control vulnerability (User). Using CWE to declare the problem leads to CWE-284. The product does not restrict or incorrectly restricts access to a resource from an unauthorized actor. Impacted is confidentiality. CVE summarizes:

WebKit in Apple iOS before 9.3.3, Safari before 9.1.2, and tvOS before 9.2.2 mishandles the location variable, which allows remote attackers to access the local filesystem via unspecified vectors.

The weakness was presented 07/18/2016 by Chris Vienneau ( with Mitsui Bussan Secure Directions as HT206900 as confirmed advisory (Website). The advisory is available at This vulnerability is handled as CVE-2016-4591 since 05/11/2016. The attack may be launched remotely. No form of authentication is required for exploitation. The technical details are unknown and an exploit is not available. This vulnerability is assigned to T1068 by the MITRE ATT&CK project. The advisory points out:

A permissions issue existed in the handling of the location variable. This was addressed though additional ownership checks.

The vulnerability scanner Nessus provides a plugin with the ID 93139 (Fedora 24 : webkitgtk4 (2016-4728dfe3ec)), which helps to determine the existence of the flaw in a target environment. It is assigned to the family Fedora Local Security Checks and running in the context l. The commercial vulnerability scanner Qualys is able to test this issue with plugin 196576 (Ubuntu Security Notification for Webkit2gtk Vulnerabilities (USN-3079-1)).

Upgrading to version 9.1.2 eliminates this vulnerability. A possible mitigation has been published immediately after the disclosure of the vulnerability.

The vulnerability is also documented in the vulnerability database at Tenable (93139). See 89671, 89672, 89673 and 89674 for similar entries.







CPE 2.3info

CPE 2.2info


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VulDB Meta Base Score: 7.5
VulDB Meta Temp Score: 7.3

VulDB Base Score: 7.5
VulDB Temp Score: 7.2
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NVD Base Score: 7.5
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Name: User
Class: Access control / User
CWE: CWE-284 / CWE-266
ATT&CK: T1068

Local: No
Remote: Yes

Availability: 🔍
Status: Not defined

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Nessus ID: 93139
Nessus Name: Fedora 24 : webkitgtk4 (2016-4728dfe3ec)
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Nessus Risk: 🔍
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OpenVAS ID: 802925
OpenVAS Name: Apple Safari Multiple Vulnerabilities December16 (Mac OS X)
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Threat Intelligenceinfo

Interest: 🔍
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Recommended: Upgrade
Status: 🔍

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Upgrade: Safari 9.1.2


05/11/2016 🔍
07/18/2016 +68 days 🔍
07/18/2016 +0 days 🔍
07/18/2016 +0 days 🔍
07/19/2016 +1 days 🔍
07/21/2016 +2 days 🔍
08/29/2016 +39 days 🔍
09/05/2022 +2198 days 🔍



Advisory: HT206900
Researcher: Chris Vienneau (
Organization: Mitsui Bussan Secure Directions
Status: Confirmed
Confirmation: 🔍

CVE: CVE-2016-4591 (🔍)
SecurityTracker: 1036343
SecurityFocus: 91830 - Apple iOS/tvOS/Safari Multiple Security Vulnerabilities

See also: 🔍


Created: 07/19/2016 04:29 PM
Updated: 09/05/2022 11:47 AM
Changes: 07/19/2016 04:29 PM (61), 03/03/2019 08:55 AM (26), 09/05/2022 11:47 AM (4)
Complete: 🔍


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