Microsoft Warns of Unpatched IE Browser Zero-Day That’s Under Active Attacks

Microsoft earlier today issued an emergency security advisory
warning millions of Windows users of a new zero-day vulnerability
in Internet Explorer (IE) browser that attackers are actively
exploiting in the wild — and there is no patch yet available for
it.

The vulnerability, tracked as CVE-2020-0674 and rated
moderated, is a remote code execution issue that exists in the way
the scripting engine handles objects in memory of Internet Explorer
and triggers through JScript.dll library.

A remote attacker can execute arbitrary code on targeted
computers and take full control over them just by convincing
victims into opening a maliciously crafted web page on the
vulnerable Microsoft browser.

“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,” the advisory
says.

“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.”

Microsoft is aware of ‘limited targeted attacks’ in the wild and
working on a fix, but until a patch is released, affected users
have been provided with workarounds and mitigation to prevent their
vulnerable systems from cyberattacks.

The affected web browsing software includes — Internet Explorer
9, Internet Explorer 10, and Internet Explorer 11 running on all
versions of Windows 10, Windows 8.1, and the recently-discontinued
Windows 7.

Workarounds: Defend Against Attacks Until A Patch Arrives

According to the advisory, preventing the loading of the
JScript.dll library can manually block the exploitation of this
vulnerability.

To restrict access to JScript.dll, run following commands on
your Windows system with administrator privileges.

For 32-bit systems:

For 32-bit systems: