Posts Tagged: Dustin Childs


12
Jan 21

Microsoft Patch Tuesday, January 2021 Edition

Microsoft today released updates to plug more than 80 security holes in its Windows operating systems and other software, including one that is actively being exploited and another which was disclosed prior to today. Ten of the flaws earned Microsoft’s most-dire “critical” rating, meaning they could be exploited by malware or miscreants to seize remote control over unpatched systems with little or no interaction from Windows users.

Most concerning of this month’s batch is probably a critical bug (CVE-2021-1647) in Microsoft’s default anti-malware suite — Windows Defender — that is seeing active exploitation. Microsoft recently stopped providing a great deal of detail in their vulnerability advisories, so it’s not entirely clear how this is being exploited.

But Kevin Breen, director of research at Immersive Labs, says depending on the vector the flaw could be trivial to exploit.

“It could be as simple as sending a file,” he said. “The user doesn’t need to interact with anything, as Defender will access it as soon as it is placed on the system.”

Fortunately, this bug is probably already patched by Microsoft on end-user systems, as the company continuously updates Defender outside of the normal monthly patch cycle.

Breen called attention to another critical vulnerability this month — CVE-2020-1660 — which is a remote code execution flaw in nearly every version of Windows that earned a CVSS score of 8.8 (10 is the most dangerous).

“They classify this vulnerability as ‘low’ in complexity, meaning an attack could be easy to reproduce,” Breen said. “However, they also note that it’s ‘less likely’ to be exploited, which seems counterintuitive. Without full context of this vulnerability, we have to rely on Microsoft to make the decision for us.” Continue reading →


10
Nov 20

Patch Tuesday, November 2020 Edition

Adobe and Microsoft each issued a bevy of updates today to plug critical security holes in their software. Microsoft’s release includes fixes for 112 separate flaws, including one zero-day vulnerability that is already being exploited to attack Windows users. Microsoft also is taking flak for changing its security advisories and limiting the amount of information disclosed about each bug.

Some 17 of the 112 issues fixed in today’s patch batch involve “critical” problems in Windows, or those that can be exploited by malware or malcontents to seize complete, remote control over a vulnerable Windows computer without any help from users.

Most of the rest were assigned the rating “important,” which in Redmond parlance refers to a vulnerability whose exploitation could “compromise the confidentiality, integrity, or availability of user data, or of the integrity or availability of processing resources.”

A chief concern among all these updates this month is CVE-2020-17087, which is an “important” bug in the Windows kernel that is already seeing active exploitation. CVE-2020-17087 is not listed as critical because it’s what’s known as a privilege escalation flaw that would allow an attacker who has already compromised a less powerful user account on a system to gain administrative control. In essence, it would have to be chained with another exploit.

Unfortunately, this is exactly what Google researchers described witnessing recently. On Oct. 20, Google released an update for its Chrome browser which fixed a bug (CVE-2020-15999) that was seen being used in conjunction with CVE-2020-17087 to compromise Windows users.

If you take a look at the advisory Microsoft released today for CVE-2020-17087 (or any others from today’s batch), you might notice they look a bit more sparse. That’s because Microsoft has opted to restructure those advisories around the Common Vulnerability Scoring System (CVSS) format to more closely align the format of the advisories with that of other major software vendors.

But in so doing, Microsoft has also removed some useful information, such as the description explaining in broad terms the scope of the vulnerability, how it can be exploited, and what the result of the exploitation might be. Microsoft explained its reasoning behind this shift in a blog post.

Not everyone is happy with the new format. Bob Huber, chief security officer at Tenable, praised Microsoft for adopting an industry standard, but said the company should consider that folks who review Patch Tuesday releases aren’t security practitioners but rather IT counterparts responsible for actually applying the updates who often aren’t able (and shouldn’t have to) decipher raw CVSS data.

“With this new format, end users are completely blind to how a particular CVE impacts them,” Huber said. “What’s more, this makes it nearly impossible to determine the urgency of a given patch. It’s difficult to understand the benefits to end-users. However, it’s not too difficult to see how this new format benefits bad actors. They’ll reverse engineer the patches and, by Microsoft not being explicit about vulnerability details, the advantage goes to attackers, not defenders. Without the proper context for these CVEs, it becomes increasingly difficult for defenders to prioritize their remediation efforts.” Continue reading →


13
Oct 20

Microsoft Patch Tuesday, October 2020 Edition

It’s Cybersecurity Awareness Month! In keeping with that theme, if you (ab)use Microsoft Windows computers you should be aware the company shipped a bevy of software updates today to fix at least 87 security problems in Windows and programs that run on top of the operating system. That means it’s once again time to backup and patch up.

Eleven of the vulnerabilities earned Microsoft’s most-dire “critical” rating, which means bad guys or malware could use them to gain complete control over an unpatched system with little or no help from users.

Worst in terms of outright scariness is probably CVE-2020-16898, which is a nasty bug in Windows 10 and Windows Server 2019 that could be abused to install malware just by sending a malformed packet of data at a vulnerable system. CVE-2020-16898 earned a CVSS Score of 9.8 (10 is the most awful).

Security vendor McAfee has dubbed the flaw “Bad Neighbor,” and in a blog post about it said a proof-of-concept exploit shared by Microsoft with its partners appears to be “both extremely simple and perfectly reliable,” noting that this sucker is imminently “wormable” — i.e. capable of being weaponized into a threat that spreads very quickly within networks.

“It results in an immediate BSOD (Blue Screen of Death), but more so, indicates the likelihood of exploitation for those who can manage to bypass Windows 10 and Windows Server 2019 mitigations,” McAfee’s Steve Povolny wrote. “The effects of an exploit that would grant remote code execution would be widespread and highly impactful, as this type of bug could be made wormable.”

Trend Micro’s Zero Day Initiative (ZDI) calls special attention to another critical bug quashed in this month’s patch batch: CVE-2020-16947, which is a problem with Microsoft Outlook that could result in malware being loaded onto a system just by previewing a malicious email in Outlook.

“The Preview Pane is an attack vector here, so you don’t even need to open the mail to be impacted,” said ZDI’s Dustin Childs.

While there don’t appear to be any zero-day flaws in October’s release from Microsoft, Todd Schell from Ivanti points out that a half-dozen of these flaws were publicly disclosed prior to today, meaning bad guys have had a jump start on being able to research and engineer working exploits. Continue reading →


8
Sep 20

Microsoft Patch Tuesday, Sept. 2020 Edition

Microsoft today released updates to remedy nearly 130 security vulnerabilities in its Windows operating system and supported software. None of the flaws are known to be currently under active exploitation, but 23 of them could be exploited by malware or malcontents to seize complete control of Windows computers with little or no help from users.

The majority of the most dangerous or “critical” bugs deal with issues in Microsoft’s various Windows operating systems and its web browsers, Internet Explorer and Edge. September marks the seventh month in a row Microsoft has shipped fixes for more than 100 flaws in its products, and the fourth month in a row that it fixed more than 120.

Among the chief concerns for enterprises this month is CVE-2020-16875, which involves a critical flaw in the email software Microsoft Exchange Server 2016 and 2019. An attacker could leverage the Exchange bug to run code of his choosing just by sending a booby-trapped email to a vulnerable Exchange server.

“That doesn’t quite make it wormable, but it’s about the worst-case scenario for Exchange servers,” said Dustin Childs, of Trend Micro’s Zero Day Initiative. “We have seen the previously patched Exchange bug CVE-2020-0688 used in the wild, and that requires authentication. We’ll likely see this one in the wild soon. This should be your top priority.”

Also not great for companies to have around is CVE-2020-1210, which is a remote code execution flaw in supported versions of Microsoft Sharepoint document management software that bad guys could attack by uploading a file to a vulnerable Sharepoint site. Security firm Tenable notes that this bug is reminiscent of CVE-2019-0604, another Sharepoint problem that’s been exploited for cybercriminal gains since April 2019.

Microsoft fixed at least five other serious bugs in Sharepoint versions 2010 through 2019 that also could be used to compromise systems running this software. And because ransomware purveyors have a history of seizing upon Sharepoint flaws to wreak havoc inside enterprises, companies should definitely prioritize deployment of these fixes, says Alan Liska, senior security architect at Recorded Future. Continue reading →


11
Aug 20

Microsoft Patch Tuesday, August 2020 Edition

Microsoft today released updates to plug at least 120 security holes in its Windows operating systems and supported software, including two newly discovered vulnerabilities that are actively being exploited. Yes, good people of the Windows world, it’s time once again to backup and patch up!

At least 17 of the bugs squashed in August’s patch batch address vulnerabilities Microsoft rates as “critical,” meaning they can be exploited by miscreants or malware to gain complete, remote control over an affected system with little or no help from users. This is the sixth month in a row Microsoft has shipped fixes for more than 100 flaws in its products.

The most concerning of these appears to be CVE-2020-1380, which is a weaknesses in Internet Explorer that could result in system compromise just by browsing with IE to a hacked or malicious website. Microsoft’s advisory says this flaw is currently being exploited in active attacks.

The other flaw enjoying active exploitation is CVE-2020-1464, which is a “spoofing” bug in virtually all supported versions of Windows that allows an attacker to bypass Windows security features and load improperly signed files. For more on this flaw, see Microsoft Put Off Fixing Zero for 2 Years.

Trend Micro’s Zero Day Initiative points to another fix — CVE-2020-1472 — which involves a critical issue in Windows Server versions that could let an unauthenticated attacker gain administrative access to a Windows domain controller and run an application of their choosing. A domain controller is a server that responds to security authentication requests in a Windows environment, and a compromised domain controller can give attackers the keys to the kingdom inside a corporate network.

“It’s rare to see a Critical-rated elevation of privilege bug, but this one deserves it,” said ZDI’S Dustin Childs. “What’s worse is that there is not a full fix available.”

Perhaps the most “elite” vulnerability addressed this month earned the distinction of being named CVE-2020-1337, and refers to a security hole in the Windows Print Spooler service that could allow an attacker or malware to escalate their privileges on a system if they were already logged on as a regular (non-administrator) user.

Satnam Narang at Tenable notes that CVE-2020-1337 is a patch bypass for CVE-2020-1048, another Windows Print Spooler vulnerability that was patched in May 2020. Narang said researchers found that the patch for CVE-2020-1048 was incomplete and presented their findings for CVE-2020-1337 at the Black Hat security conference earlier this month. More information on CVE-2020-1337, including a video demonstration of a proof-of-concept exploit, is available here. Continue reading →


1
May 14

Microsoft Issues Fix for IE Zero-Day, Includes XP Users

Microsoft has issued an emergency security update to fix a zer0-day vulnerability that is present in all versions of its Internet Explorer Web browser and that is actively being exploited. In an unexpected twist, the company says Windows XP users also will get the update, even though Microsoft officially ceased supporting XP last month.

IEwarning

The rushed patch comes less than five days after the software giant warned users about active attacks that attempt to exploit a previously unknown security flaw in every supported version of IE. This flaw can be used to silently install malicious software without any help from users, save for perhaps browsing to a hacked or malicious site.

“We have made the decision to issue a security update for Windows XP users,” writes Dustin C. Childs, group manager, response communications at Microsoft. “Windows XP is no longer supported by Microsoft, and we continue to encourage customers to migrate to a modern operating system, such as Windows 7 or 8.1. Additionally, customers are encouraged to upgrade to the latest version of Internet Explorer, IE 11.”

Microsoft says the majority of customers have automatic updates enabled and will not need to take any action because protections will be downloaded and installed automatically. Windows users who don’t take advantage of the automatic updates feature of Windows (or who don’t wish to wait around for it to install the patch) can do so by visiting Windows Update.


28
Dec 12

Attackers Target Internet Explorer Zero-Day Flaw

Attackers are breaking into Microsoft Windows computers using a newly discovered vulnerability in Internet Explorer, security experts warn. While the flaw appears to have been used mainly in targeted attacks so far, this vulnerability could become more widely exploited if incorporated into commercial crimeware kits sold in the underground.

IEwarningIn a blog posting Friday evening, Milpitas, Calif. based security vendor FireEye said it found that the Web site for the Council on Foreign Relations was compromised and rigged to exploit a previously undocumented flaw in IE8 to install malicious software on vulnerable PCs used to browse the site.

According to FireEye, the attack uses Adobe Flash to exploit a vulnerability in the latest (fully-patched) version of IE8. Dustin Childs, group manager for response communications at Microsoft, said the vulnerability appears to exist in previous versions of IE.

“We are actively investigating reports of a small, targeted issue affecting Internet Explorer 6-8,” Childs said in an emailed statement. “We will take appropriate action to help keep customers protected once our analysis is complete. People using Internet Explorer 9-10 are not impacted.”

As FireEye notes, this is another example of a “watering hole” attack, which involves the targeted compromise of legitimate websites thought to be of interest to or frequented by end users who belong to organizations that attackers wish to infiltrate. Earlier this year, I wrote about similar zero-day attacks against visitors to the Web sites of the National Democratic Institute, The Carter Center, and Radio Free Europe.

Update, Dec. 30, 9:25 a.m. ET: Microsoft has officially acknowledged this vulnerability in an advisory, which contains some advice for IE users about how to mitigate the threat. As IE versions 9 and 10 are not impacted, users running Windows Vista or higher can upgrade to the latest browser version here.

Update, Jan.1 8:56 p.m. ET: Microsoft’s advisory now includes a link to a stopgap “FixIt” solution that may help to blunt attacks until the company issues an official patch for this vulnerability.