Google Chrome up to 38 Blink Serializer::doSerialize privileges management

CVSS Meta Temp Score
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6.4$0-$5k0.00

A vulnerability was found in Google Chrome up to 38 (Web Browser). It has been rated as critical. Affected by this issue is the function Serializer::doSerialize of the component Blink. The manipulation with an unknown input leads to a privileges management vulnerability. Using CWE to declare the problem leads to CWE-269. The product does not properly assign, modify, track, or check privileges for an actor, creating an unintended sphere of control for that actor. Impacted is confidentiality, integrity, and availability.

The weakness was published 11/11/2016 by Berend-Jan Wever (aka. SkyLined) as Google Chrome blink Serializer::doSerialize bad cast details as not defined mailinglist post (Full-Disclosure). The advisory is available at seclists.org. The vendor was not involved in the coordination of the public release. The mailinglist post contains:

December 2014: ZDI, iDefense and EIP all either reject the submission or fail to respond.
The attack may be launched remotely. No form of authentication is required for exploitation. Technical details as well as a public exploit are known. This vulnerability is assigned to T1068 by the MITRE ATT&CK project. The advisory points out:
When serializing JavaScript objects for sending to another window using the `postMessage` method, the code in blink does not handle `Symbol` objects correctly and attempts to serialize this kind of object as a regular object, which results in a bad cast. An attacker that can trigger this issue may be able to execute arbitrary code.

A public exploit has been developed by Berend-Jan Wever (aka. SkyLined) in Javascript and been published immediately after the advisory. The exploit is available at seclists.org. It is declared as proof-of-concept. As 0-day the estimated underground price was around $25k-$100k. The real existence of this vulnerability is still doubted at the moment. The code used by the exploit is:

<script>
  postMessage(Symbol());
</script>
The advisory illustrates:
An attacker would need to get a target user to open a specially crafted webpage.

Upgrading eliminates this vulnerability. The upgrade is hosted for download at chrome.google.com. It is possible to mitigate the problem by applying the configuration setting Disable JavaScript. The best possible mitigation is suggested to be the change of configuration settings.

Productinfo

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Vendor

Name

Version

License

CPE 2.3info

CPE 2.2info

CVSSv4info

VulDB CVSS-B Score: 🔍
VulDB CVSS-BT Score: 🔍
VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv3info

VulDB Meta Base Score: 7.3
VulDB Meta Temp Score: 6.4

VulDB Base Score: 7.3
VulDB Temp Score: 6.4
VulDB Vector: 🔍
VulDB Reliability: 🔍

CVSSv2info

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VulDB Base Score: 🔍
VulDB Temp Score: 🔍
VulDB Reliability: 🔍

Exploitinginfo

Class: Privileges management
CWE: CWE-269 / CWE-266
ATT&CK: T1068

Local: No
Remote: Yes

Availability: 🔍
Access: Public
Status: Proof-of-Concept
Author: Berend-Jan Wever (aka. SkyLined)
Programming Language: 🔍
Download: 🔍
Price Prediction: 🔍
Current Price Estimation: 🔍

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Threat Intelligenceinfo

Interest: 🔍
Active Actors: 🔍
Active APT Groups: 🔍

Countermeasuresinfo

Recommended: Config
Status: 🔍

0-Day Time: 🔍
Exploit Delay Time: 🔍

Upgrade: chrome.google.com
Config: Disable JavaScript

Timelineinfo

11/11/2016 🔍
11/11/2016 +0 days 🔍
11/12/2016 +1 days 🔍
05/30/2019 +929 days 🔍

Sourcesinfo

Vendor: google.com
Product: google.com

Advisory: Google Chrome blink Serializer::doSerialize bad cast details
Researcher: Berend-Jan Wever (aka. SkyLined)
Status: Not defined
Disputed: 🔍
scip Labs: https://www.scip.ch/en/?labs.20161013

Entryinfo

Created: 11/12/2016 10:12
Updated: 05/30/2019 16:05
Changes: 11/12/2016 10:12 (57), 05/30/2019 16:05 (2)
Complete: 🔍

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