Scripting Engine Memory Corruption Vulnerability

Vulnerability

Overview

CVE-2020-1172 is a remote code execution vulnerability in the ChakraCore scripting engine, which is used by Microsoft Edge and other applications. The flaw arises from the way ChakraCore handles objects in memory, leading to memory corruption that an attacker can exploit to execute arbitrary code in the context of the current user [1][2]. The root cause is an improper object-handling routine that can be triggered by specially crafted web content.

Exploitation

Prerequisites

An attacker would need to host a malicious website (or inject content into a compromised site) that contains JavaScript designed to trigger the memory corruption. No authentication is required; the victim simply visits the page. The vulnerability can be exploited remotely over the network, and the attacker gains code execution at the privilege level of the user running the browser or application that uses ChakraCore [2].

Impact

Successful exploitation allows the attacker to perform actions as the current user. If that user has administrative rights, the attacker can take full control of the system, install programs, view/change/delete data, or create new accounts with full user rights [2]. The impact is limited to the user's permissions, but in many enterprise scenarios users have elevated privileges, making this a critical risk.

Mitigation

Microsoft released a security update in September 2020 that modifies how ChakraCore handles objects in memory, fixing the vulnerability [1]. Users should apply the update via Windows Update or by updating any software that embeds ChakraCore. No workarounds are documented; the only mitigation is to install the patch.