Microsoft issues emergency Windows patch to disable Intel’s buggy Spectre fix

If your Windows PC seems buggier than usual after the recent round of Spectre patches, you might want to download this.

By   Senior Editor, PCWorld

If you’ve noticed any unexpected reboots or PC instability as a result of the recent Spectre patches, there’s a solution: Microsoft has issued an emergency Windows patch that rolls back the recent Spectre mitigations.

Confused? It’s a bit complicated. After the intial Spectre and Meltdown vulnerabilites were disclosed, both Intel and Microsoft hustled out patches to mitigate the problem. Unfortunately, Intel’s latest microcode updates—and the BIOS updates from PC makers based upon them—were themselves buggy, causing instability, reboots, and data loss in some PCs.

Microsoft’s latest patch (KB4078130) allows people with affected systems to download the patch via the Microsoft Update Catalog, which disables the mitigations for the “Spectre variant 2.”

Note that the patch notes specifically state that you should run this patch “if you are running an impacted device” (emphasis ours). In other words, if your system is working normally, don’t bother downloading this patch. This is what Microsoft calls an “out of band” patch, and it doesn’t appear that it will be made available via Windows Update, either.

Why should you consider it? Intel has warned previously that the faulty patch can sometimes cause data loss and corruption, and Microsoft is saying the same: “Our own experience is that system instability can in some circumstances cause data loss or corruption,” the patch notes state.

There’s another wrinkle, though. As part of the patch, Microsoft is allowing users to edit the Windows registry to toggle the mitigations on or off. (Instructions are here.) It’s possible to toggle Microsoft’s patch off, and then, when Intel solves its own patching problem, re-enable it. That scenario is actually what Microsoft recommends—again, only if you’ve noticed system instability and want to take action against it.

Toggling the mitigations on and off is also a feature of the latest InSpectre utility.

As Bleeping Computer noted, system makers such as Dell and HP also advise rolling back their own BIOS patches to an earlier version, which they’re redeployed. It’s all horrendously confusing for consumers and IT organizations alike. Fortunately, at least, there haven’t been any public cases of these vulnerabilities being exploited, Microsoft says.

What should you do? There’s no one-size-fits-all answer to this question. But we can tell you what we’re doing: if a PC is working as expected, we’re leaving it patched and in place. If you’re backing up your data (to Remote Backup Services or an external drive) chances are your most crucial data will be saved in case your system goes down unexpectedly. Obviously, install Microsoft’s emergency Windows patch if you’re running into system issues. There’s no perfect solution—if you’re more paranoid than we are, feel free to deploy the patch even if your PC hasn’t hiccuped.

Microsoft Issues Emergency Out-Of-Band Update to Fix “Crazy Bad” Vulnerability

By 

Patched Microsoft Malware Protection Engine

In an emergency out-of-band update released late last night, Microsoft fixed a vulnerability in the Microsoft Malware Protection Engine discovered by two Google security experts over the weekend, and which the two described as “crazy bad” and “the worst Windows remote code exec in recent memory.”

While initially the two Google experts didn’t reveal what Windows feature the bug was found in, the veil of mystery lifted yesterday when both Microsoft and the two experts shared more details about the issue.

Vulnerability affects Microsoft Malware Protection Engine

As per the two sources, the bug affects the Microsoft Malware Protection Engine (MsMpEng), a core service that ships with Windows 7, Windows 8.1, Windows 10, and Windows Server 2016, and which is the core of many of Microsoft security tools, such as:

  • Windows Defender
  • Microsoft Security Essentials
  • Microsoft Endpoint Protection
  • Microsoft System Center Endpoint Protection
  • Windows Intune Endpoint Protection
  • Microsoft Forefront Security for SharePoint Service Pack 3
  • Microsoft Forefront Endpoint Protection 2010

According to the Google experts, the bug is a “type confusion” vulnerability in NScript, the MsMpEng component that handles “any filesystem or network activity that looks like JavaScript.”

The two experts say that NScript mishandles how it interprets some JavaScript object types, which allows them to deliver an exploit that can use the Microsoft Malware Protection Engine to execute malicious code.

Vulnerability is trivially exploitable

The researchers say the issue can be exploited with no user interaction needed.

This includes scenarios such as sending an email with the exploit included in the message’s body, hosting malicious JavaScript code inside a web page, or by delivering a JS exploit to thousands or millions on users, via ads on reputable sites.

“Vulnerabilities in MsMpEng are among the most severe possible in Windows, due to the privilege, accessibility, and ubiquity of the service,” Tavis Ormandy, one of the Google researchers says.

This is because the service runs without sandboxing — a basic and very efficient security feature —, but also because the service runs as
NT AUTHORITY\SYSTEM, a system-level user with no limitations.

Furthermore, the service is included by default on all recent Windows operating system, exposing hundreds of millions of PCs to remote hacking.

Microsoft patches issue within days

Unlike past incidents, where Microsoft has allowed exploited zero-day vulnerabilities to fester in the wild without being bothered to deliver a patch for months, this time around, the company moved lightning fast to address the issue.

In just a few days, the company had prepared and already shipped a patch to fix the vulnerable MsMpEng service.

According to a Microsoft advisory, the first version of the Microsoft Malware Protection Engine affected by this flaw is v1.1.13701.0. The issue has been patched in v1.1.13704.0, released a few hours ago, and which has already reached some users (screenshot above).

Microsoft also said that on latest Windows platforms, the risk of exploitation should be lower if the user has turned on Windows CFG (Control Flow Guard), a security feature that can make exploitation of memory-based vulnerabilities much harder.

The vulnerability is tracked as CVE-2017-0290. The two Google researchers also released proof-of-concept exploit code. The entire exploit fits in a tweet. To help spread the word about this issue, US-CERT has also released an accompanying alert.

Windows 10 included a password manager complete with massive password-stealing potential

 

Stealing password from codeMicrosoft has been bundling a password manager that features a dangerous flaw with some versions of Windows 10, a Google security researcher has revealed. Tavis Ormandy noticed that his copy of Windows 10 included Keeper, which he had previously found to be injecting privileged UI into pages.The version that Microsoft was including with Windows 10 featured the same bug. What does this mean? In short, it allows any website to steal passwords from you.

Keeper was included in some Windows 10 installations as a browser plugin, and it included the very same vulnerability that Ormandy had reported nearly a year and half earlier. With little more than a couple of very easily implemented tweaks, he found that it was possible to steal passwords that are stored within Keeper.

Ormandy shared details of the vulnerability on Twitter:

I created a new Windows 10 VM with a pristine image from MSDN, and noticed a third party password manager is now installed by default. It didn’t take long to find a critical vulnerability. https://bugs.chromium.org/p/project-zero/issues/detail?id=1481 

 He also posted on the Project Zero page, saying:

I recently created a fresh Windows 10 VM with a pristine image from MSDN, and found that a password manager called “Keeper” is now installed by default. I’m not the only person who has noticed this:

https://www.reddit.com/r/Windows10/comments/6dpj78/keeper_password_manager_comes_preinstalled_now/

I assume this is some bundling deal with Microsoft. I’ve heard of Keeper, I remember filing a bug a while ago about how they were injecting privileged UI into pages (   issue 917   ). I checked and, they’re doing the same thing again with this version. I think I’m being generous considering this a new issue that qualifies for a ninety day disclosure, as I literally just changed the selectors and the same attack works.

Nevertheless, this is a complete compromise of Keeper security, allowing any website to steal any password.

Having been made aware of the problem, the developers of Keeper issued a patch within 24 hours, saying:

This potential vulnerability requires a Keeper user to be lured to a malicious website while logged into the browser extension, and then fakes user input by using a ‘clickjacking’ technique to execute privileged code within the browser extension.

There have been no reports of the vulnerability having been exploited.

Image credit: Maddas / Shutterstock

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