Scripting Engine Memory Corruption Vulnerability CVE-2020-0674

February 21, 2020

A remote code execution vulnerability exists in the way that the scripting engine handles objects in memory in Internet Explorer, aka ‘Scripting Engine Memory Corruption Vulnerability’. The vulnerability could corrupt memory in such a way that an attacker could execute arbitrary code in the context of the current user. An attacker who successfully exploited the vulnerability could gain the same user rights as the current user. If the current user is logged on with administrative user rights, an attacker who successfully exploited the vulnerability could take control of an affected system. An attacker could then install programs; view, change, or delete data; or create new accounts with full user rights.

Observing the exploit code the parameter in sort function is not added to the garbage collection hence it can be used later to achieve arbitrary code execution.

In a web-based attack scenario, an attacker could host a specially crafted website that is designed to exploit the vulnerability through Internet Explorer and then convince a user to view the website. An attacker could also embed an ActiveX control marked “safe for initialization” in an application or Microsoft Office document that hosts the IE rendering engine. The attacker could also take advantage of compromised websites and websites that accept or host user-provided content or advertisements. These websites could contain specially crafted content that could exploit the vulnerability.

The attacker connects to following malicious domains.

The IE crashes indicating the vulnerable dll

SonicWall Capture Labs Threat Research team provides protection against this vulnerability with the following signature:

  • IPS 14744 Scripting Engine Memory Corruption Vulnerability (CVE-2020-0674)

Microsoft hasa issued a patch for this vulnerability.

IoCs :