CVE-2018-4441 : Detail

CVE-2018-4441

8.8
/
High
Overflow
91.83%V3
Network
2019-04-03
15h43 +00:00
2019-04-03
15h43 +00:00
CVE.org
NVD
Notifications for a CVE
Stay informed of any changes for a specific CVE.
Notifications manage

CVE Descriptions

A memory corruption issue was addressed with improved memory handling. This issue affected versions prior to iOS 12.1.1, tvOS 12.1.1, watchOS 5.1.2, Safari 12.0.2, iTunes 12.9.2 for Windows, iCloud for Windows 7.9.

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 8.8 HIGH CVSS:3.0/AV:N/AC:L/PR:N/UI:R/S:U/C:H/I:H/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.

High

There is a total loss of integrity, or a complete loss of protection. For example, the attacker is able to modify any/all files protected by the impacted component. Alternatively, only some files can be modified, but malicious modification would present a direct, serious consequence to 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 6.8 AV:N/AC:M/Au:N/C:P/I:P/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.
EPSS First.org

Exploit information

Exploit Database EDB-ID : 46522

Publication date : 2019-03-07 23h00 +00:00
Author : Specter
EDB Verified : No

PS4 6.20 WebKit Code Execution PoC ============== This repo contains a proof-of-concept (PoC) RCE exploit targeting the PlayStation 4 on firmware 6.20 leveraging CVE-2018-4441. The exploit first establishes an arbitrary read/write primitive as well as an arbitrary object address leak in `wkexploit.js`. It will then setup a framework to run ROP chains in `index.html` and by default will provide two hyperlinks to run test ROP chains - one for running the `sys_getpid()` syscall, and the other for running the `sys_getuid()` syscall to get the PID and user ID of the process respectively. Each file contains a comment at the top giving a brief explanation of what the file contains and how the exploit works. Credit for the bug discovery is to lokihardt from Google Project Zero (p0). The bug report can be found [here](https://bugs.chromium.org/p/project-zero/issues/detail?id=1685&desc=2). Note: It's been patched in the 6.50 firmware update. Files ============== Files in order by name alphabetically; * `index.html` - Contains post-exploit code, going from arb. R/W -> code execution. * `rop.js` - Contains a framework for ROP chains. * `syscalls.js` - Contains an (incomplete) list of system calls to use for post-exploit stuff. * `wkexploit.js` - Contains the heart of the WebKit exploit. Notes ============== * This vulnerability was patched in 6.50 firmware! * This only gives you code execution in **userland**. This is **not** a jailbreak nor a kernel exploit, it is only the first half. * This exploit targets firmware 6.20. It should work on lower firmwares however the gadgets will need to be ported, and the `p.launchchain()` method for code execution may need to be swapped out. * In my tests the exploit as-is is pretty stable, but it can become less stable if you add a lot of objects and such into the exploit. This is part of the reason why `syscalls.js` contains only a small number of system calls. Usage ============== Setup a web-server hosting these files on localhost using xampp or any other program of your choosing. Additionally, you could host it on a server. You can access it on the PS4 by either; 1) Fake DNS spoofing to redirect the manual page to the exploit page, or 2) Using the web browser to navigate to the exploit page (not always possible). Vulnerability Credit ============== I wrote the exploit however I did not find the vulnerability, as mentioned above the bug (CVE-2018-4441) was found by lokihardt from Google Project Zero (p0) and was disclosed via the Chromium public bug tracker. Resources ============== [Chromium Bug Report](https://bugs.chromium.org/p/project-zero/issues/detail?id=1685&desc=2) - The vulnerability. [Phrack: Attacking JavaScript Engines by saelo](http://www.phrack.org/papers/attacking_javascript_engines.html) - A life saver. Exploiting this would have been about 1500x more difficult without this divine paper. Thanks ============== lokihardt - The vulnerability st4rk - Help with the exploit qwertyoruiop - WebKit School saelo - Phrack paper Download: https://gitlab.com/exploit-database/exploitdb-bin-sploits/-/raw/main/bin-sploits/46522.zip
Exploit Database EDB-ID : 46072

Publication date : 2019-01-01 23h00 +00:00
Author : Google Security Research
EDB Verified : Yes

/* bool JSArray::shiftCountWithArrayStorage(VM& vm, unsigned startIndex, unsigned count, ArrayStorage* storage) { unsigned oldLength = storage->length(); RELEASE_ASSERT(count <= oldLength); // If the array contains holes or is otherwise in an abnormal state, // use the generic algorithm in ArrayPrototype. if ((storage->hasHoles() && this->structure(vm)->holesMustForwardToPrototype(vm, this)) || hasSparseMap() || shouldUseSlowPut(indexingType())) { return false; } if (!oldLength) return true; unsigned length = oldLength - count; storage->m_numValuesInVector -= count; storage->setLength(length); Considering the comment, I think the method is supposed to prevent an array with holes from going through to the code "storage->m_numValuesInVector -= count". But that kind of arrays actually can get there by only having the holesMustForwardToPrototype method return false. Unless the array has any indexed accessors on it or Proxy objects in the prototype chain, the method will just return false. So "storage->m_numValuesInVector" can be controlled by the user. In the PoC, it changes m_numValuesInVector to 0xfffffff0 that equals to the new length, making the hasHoles method return false, leading to OOB reads/writes in the JSArray::unshiftCountWithArrayStorage method. PoC: */ function main() { let arr = [1]; arr.length = 0x100000; arr.splice(0, 0x11); arr.length = 0xfffffff0; arr.splice(0xfffffff0, 0, 1); } main();

Products Mentioned

Configuraton 0

Apple>>Safari >> Version To (excluding) 12.0.2

Apple>>Iphone_os >> Version To (excluding) 12.1.1

Apple>>Tvos >> Version To (excluding) 12.1.1

Apple>>Watchos >> Version To (excluding) 5.1.2

Configuraton 0

Apple>>Icloud >> Version To (excluding) 7.9

Apple>>Itunes >> Version To (excluding) 12.9.2

Microsoft>>Windows >> Version -

References