• Yet another JScript vulnerability

    Internet Explorer, the gift that keeps on giving.

    Looks like we have a brand new JScript bug. According to ADV200001:

    A remote code execution vulnerability exists in the way that the scripting engine handles objects in memory in Internet Explorer. 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.

    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, for example, by sending an email.

    The fix, documented in the Security Advisory, is to cut off JScript. Again.

    Is there an update to address this vulnerability?

    No, Microsoft is aware of this vulnerability and working on a fix. Our standard policy is to release security updates on Update Tuesday, the second Tuesday of each month. This predictable schedule allows for partner quality assurance and IT planning, which helps maintain the Windows ecosystem as a reliable, secure choice for our customers.

    Is Microsoft aware of attacks based on this vulnerabilty?

    Yes, Microsoft is aware of limited targeted attacks.

    At least they aren’t going to try to chase it down with four progressively buggy patches, like they did in September and October.

    You folks trying to work with IE are going to have an interesting weekend, yes?

    UPDATE: Catalin Cimpanu has more details on ZDNet.

    UPDATE: Microsoft has assigned the CVE number CVE-2020-0674