Category: Trend Micro Zero Day Initiative

Microsoft today released software updates to plug 100 security holes in its Windows operating systems and other software, including a zero-day vulnerability that is already being used in active attacks. Not to be outdone, Apple has released a set of important updates addressing two zero-day vulnerabilities that are being used to attack iPhones, iPads and Macs.

On April 7, Apple issued emergency security updates to fix two weaknesses that are being actively exploited, including CVE-2023-28206, which can be exploited by apps to seize control over a device. CVE-2023-28205 can be used by a malicious or hacked website to install code.

Both vulnerabilities are addressed in iOS/iPadOS 16.4.1, iOS 15.5.7, and macOS 12.6.5 and 11.7.6. If you use Apple devices and you don’t have automatic updates enabled (they are on by default), you should probably take care of that soon as detailed instructions on how to attack CVE-2023-28206 are now public.

Microsoft’s bevy of 100 security updates released today include CVE-2023-28252, which is a weakness in Windows that Redmond says is under active attack. The vulnerability is in the Windows Common Log System File System (CLFS) driver, a core Windows component that was the source of attacks targeting a different zero-day vulnerability in February 2023.

“If it seems familiar, that’s because there was a similar 0-day patched in the same component just two months ago,” said Dustin Childs at the Trend Micro Zero Day Initiative. “To me, that implies the original fix was insufficient and attackers have found a method to bypass that fix. As in February, there is no information about how widespread these attacks may be. This type of exploit is typically paired with a code execution bug to spread malware or ransomware.”

According to the security firm Qualys, this vulnerability has been leveraged by cyber criminals to deploy Nokoyawa ransomware.

“This is a relatively new strain for which there is some open source intel to suggest that it is possibly related to Hive ransomware – one of the most notable ransomware families of 2021 and linked to breaches of over 300+ organizations in a matter of just a few months,” said Bharat Jogi, director of vulnerability and threat research at Qualys.

Jogi said while it is still unclear which exact threat actor is targeting CVE-2023-28252, targets have been observed in South and North America, regions across Asia and at organizations in the Middle East.

Satnam Narang at Tenable notes that CVE-2023-28252 is also the second CLFS zero-day disclosed to Microsoft by researchers from Mandiant and DBAPPSecurity (CVE-2022-37969), though it is unclear if both of these discoveries are related to the same attacker.

Seven of the 100 vulnerabilities Microsoft fixed today are rated “Critical,” meaning they can be used to install malicious code with no help from the user. Ninety of the flaws earned Redmond’s slightly less-dire “Important” label, which refers to weaknesses that can be used to undermine the security of the system but which may require some amount of user interaction.

Narang said Microsoft has rated nearly 90% of this month’s vulnerabilities as “Exploitation Less Likely,” while just 9.3% of flaws were rated as “Exploitation More Likely.” Kevin Breen at Immersive Labs zeroed in on several notable flaws in that 9.3%, including CVE-2023-28231, a remote code execution vulnerability in a core Windows network process (DHCP) with a CVSS score of 8.8.

“‘Exploitation more likely’ means it’s not being actively exploited but adversaries may look to try and weaponize this one,” Breen said. “Micorosft does note that successful exploitation requires an attacker to have already gained initial access to the network. This could be via social engineering, spear phishing attacks, or exploitation of other services.”

Breen also called attention to CVE-2023-28220 and CVE-2023-28219 — a pair of remote code execution vulnerabilities affecting Windows Remote Access Servers (RAS) that also earned Microsoft’s “exploitation more likely” label.

“An attacker can exploit this vulnerability by sending a specially crafted connection request to a RAS server, which could lead to remote code execution,” Breen said. While not standard in all organizations, RAS servers typically have direct access from the Internet where most users and services are connected. This makes it extremely enticing for attackers as they don’t need to socially engineer their way into an organization. They can simply scan the internet for RAS servers and automate the exploitation of vulnerable devices.”

For more details on the updates released today, see the SANS Internet Storm Center roundup. If today’s updates cause any stability or usability issues in Windows, AskWoody.com will likely have the lowdown on that.

Please consider backing up your data and/or imaging your system before applying any updates. And feel free to sound off in the comments if you experience any problems as a result of these patches.

Microsoft is sending the world a whole bunch of love today, in the form of patches to plug dozens of security holes in its Windows operating systems and other software. This year’s special Valentine’s Day Patch Tuesday includes fixes for a whopping three different “zero-day” vulnerabilities that are already being used in active attacks.

Microsoft’s security advisories are somewhat sparse with details about the zero-day bugs. Redmond flags CVE-2023-23376 as an “Important” elevation of privilege vulnerability in the Windows Common Log File System Driver, which is present in Windows 10 and 11 systems, as well as many server versions of Windows.

“Sadly, there’s just a little solid information about this privilege escalation,” said Dustin Childs, head of threat awareness at Trend Micro’s Zero Day Initiative. “Microsoft does note that the vulnerability would allow an attacker to exploit code as SYSTEM, which would allow them to completely take over a target. This is likely being chained with a remote code execution bug to spread malware or ransomware. Considering this was discovered by Microsoft’s Threat Intelligence Center, it could mean it was used by advanced threat actors. Either way, make sure you test and roll these fixes quickly.”

The zero-day CVE-2023-21715 is a weakness in Microsoft Office that Redmond describes as a “security feature bypass vulnerability.”

“Microsoft lists this as under active exploit, but they offer no info on how widespread these exploits may be,” Childs said. “Based on the write-up, it sounds more like a privilege escalation than a security feature bypass, but regardless, active attacks in a common enterprise application shouldn’t be ignored. It’s always alarming when a security feature is not just bypassed but exploited. Let’s hope the fix comprehensively addresses the problem.”

The third zero-day flaw already seeing exploitation is CVE-2023-21823, which is another elevation of privilege weakness — this one in the Microsoft Windows Graphic component. Researchers at cybersecurity forensics firm Mandiant were credited with reporting the bug.

Kevin Breen, director of cyber threat research at Immersive Labs, pointed out that the security bulletin for CVE-2023-21823 specifically calls out OneNote as being a vulnerable component for the vulnerability.

“In recent weeks, we have seen an increase in the use of OneNote files as part of targeted malware campaigns,” Breen said. “Patches for this are delivered via the app stores and not through the typical formats, so it’s important to double check your organization’s policies.”

Microsoft fixed another Office vulnerability in CVE-2023-21716, which is a Microsoft Word bug that can lead to remote code execution — even if a booby-trapped Word document is merely viewed in the preview pane of Microsoft Outlook. This security hole has a CVSS (severity) score of 9.8 out of a possible 10.

Microsoft also has more valentines for organizations that rely on Microsoft Exchange Server to handle email. Redmond patched three Exchange Server flaws (CVE-2023-21706, CVE-2023-21707, and CVE-2023-21529), all of which Microsoft says are remote code execution flaws that are likely to be exploited.

Microsoft said authentication is required to exploit these bugs, but then again threat groups that attack Exchange vulnerabilities also tend to phish targets for their Exchange credentials.

Microsoft isn’t alone in dropping fixes for scary, ill-described zero-day flaws. Apple on Feb. 13 released an update for iOS that resolves a zero-day vulnerability in Webkit, Apple’s open source browser engine. Johannes Ullrich at the SANS Internet Storm Center notes that in addition to the WebKit problem, Apple fixed a privilege escalation issue. Both flaws are fixed in iOS 16.3.1.

“This privilege escalation issue could be used to escape the browser sandbox and gain full system access after executing code via the WebKit vulnerability,” Ullrich warned.

On a lighter note (hopefully), Microsoft drove the final nail in the coffin for Internet Explorer 11 (IE11). According to Redmond, the out-of-support IE11 desktop application was permanently disabled on certain versions of Windows 10 on February 14, 2023 through a Microsoft Edge update.

“All remaining consumer and commercial devices that were not already redirected from IE11 to Microsoft Edge were redirected with the Microsoft Edge update. Users will be unable to reverse the change,” Microsoft explained. “Additionally, redirection from IE11 to Microsoft Edge will be included as part of all future Microsoft Edge updates. IE11 visual references, such as the IE11 icons on the Start Menu and taskbar, will be removed by the June 2023 Windows security update (“B” release) scheduled for June 13, 2023.”

For a more granular rundown on the updates released today, see the SANS Internet Storm Center roundup. If today’s updates cause any stability or usability issues in Windows, AskWoody.com will likely have the lowdown on that.

Please consider backing up your data and/or imaging your system before applying any updates. And feel free to sound off in the comments if you experience any problems as a result of these patches.

Microsoft on Tuesday released software updates to fix 60 security vulnerabilities in its Windows operating systems and other software, including a zero-day flaw in all supported Microsoft Office versions on all flavors of Windows that’s seen active exploitation for at least two months now. On a lighter note, Microsoft is officially retiring its Internet Explorer (IE) web browser, which turns 27 years old this year.

Three of the bugs tackled this month earned Microsoft’s most dire “critical” label, meaning they can be exploited remotely by malware or miscreants to seize complete control over a vulnerable system. On top of the critical heap this month is CVE-2022-30190, a vulnerability in the Microsoft Support Diagnostics Tool (MSDT), a service built into Windows.

Dubbed “Follina,” the flaw became public knowledge on May 27, when a security researcher tweeted about a malicious Word document that had surprisingly low detection rates by antivirus products. Researchers soon learned that the malicious document was using a feature in Word to retrieve a HTML file from a remote server, and that HTML file in turn used MSDT to load code and execute PowerShell commands.

“What makes this new MS Word vulnerability unique is the fact that there are no macros exploited in this attack,” writes Mayuresh Dani, manager of threat research at Qualys. “Most malicious Word documents leverage the macro feature of the software to deliver their malicious payload. As a result, normal macro-based scanning methods will not work to detect Follina. All an attacker needs to do is lure a targeted user to download a Microsoft document or view an HTML file embedded with the malicious code.”

Kevin Beaumont, the researcher who gave Follina its name, penned a fairly damning account and timeline of Microsoft’s response to being alerted about the weakness. Beaumont says researchers in March 2021 told Microsoft they were able achieve the same exploit using Microsoft Teams as an example, and that Microsoft silently fixed the issue in Teams but did not patch MSDT in Windows or the attack vector in Microsoft Office.

Beaumont said other researchers on April 12, 2022 told Microsoft about active exploitation of the MSDT flaw, but Microsoft closed the ticket saying it wasn’t a security issue. Microsoft finally issued a CVE for the problem on May 30, the same day it released recommendations on how to mitigate the threat from the vulnerability.

Microsoft also is taking flak from security experts regarding a different set of flaws in its Azure cloud hosting platform. Orca Security said that back on January 4 it told Microsoft about a critical bug in Azure’s Synapse service that allowed attackers to obtain credentials to other workspaces, execute code, or leak customer credentials to data sources outside of Azure.

In an update to their research published Tuesday, Orca researchers said they were able to bypass Microsoft’s fix for the issue twice before the company put a working fix in place.

“In previous cases, vulnerabilities were fixed by the cloud providers within a few days of our disclosure to the affected vendor,” wrote Orca’s Avi Shua. “Based on our understanding of the architecture of the service, and our repeated bypasses of fixes, we think that the architecture contains underlying weaknesses that should be addressed with a more robust tenant separation mechanism. Until a better solution is implemented, we advise that all customers assess their usage of the service and refrain from storing sensitive data or keys in it.”

Amit Yoran, CEO of Tenable and a former U.S. cybersecurity czar, took Microsoft to task for silently patching an issue Tenable reported in the same Azure Synapse service.

“It was only after being told that we were going to go public, that their story changed…89 days after the initial vulnerability notification…when they privately acknowledged the severity of the security issue,” Yoran wrote in a post on LinkedIn. “To date, Microsoft customers have not been notified. Without timely and detailed disclosures, customers have no idea if they were, or are, vulnerable to attack…or if they fell victim to attack prior to a vulnerability being patched. And not notifying customers denies them the opportunity to look for evidence that they were or were not compromised, a grossly irresponsible policy.”

Also in the critical and notable stack this month is CVE-2022-30136, which is a remote code execution flaw in the Windows Network File System (NFS version 4.1) that earned a CVSS score of 9.8 (10 being the worst). Microsoft issued a very similar patch last month for vulnerabilities in NFS versions 2 and 3.

“This vulnerability could allow a remote attacker to execute privileged code on affected systems running NFS. On the surface, the only difference between the patches is that this month’s update fixes a bug in NFSV4.1, whereas last month’s bug only affected versions NSFV2.0 and NSFV3.0,” wrote Trend Micro’s Zero Day Initiative. “It’s not clear if this is a variant or a failed patch or a completely new issue. Regardless, enterprises running NFS should prioritize testing and deploying this fix.”

Beginning today, Microsoft will officially stop supporting most versions of its Internet Explorer Web browser, which was launched in August 1995. The IE desktop application will be disabled, and Windows users who wish to stick with a Microsoft browser are encouraged to move to Microsoft Edge with IE mode, which will be supported through at least 2029.

For a closer look at the patches released by Microsoft today and indexed by severity and other metrics, check out the always-useful Patch Tuesday roundup from the SANS Internet Storm Center. And it’s not a bad idea to hold off updating for a few days until Microsoft works out any kinks in the updates: AskWoody.com usually has the dirt on any patches that may be causing problems for Windows users.

As always, please consider backing up your system or at least your important documents and data before applying system updates. And if you run into any problems with these updates, please drop a note about it here in the comments.

Microsoft today released updates to fix at least 74 separate security problems in its Windows operating systems and related software. This month’s patch batch includes fixes for seven “critical” flaws, as well as a zero-day vulnerability that affects all supported versions of Windows.

By all accounts, the most urgent bug Microsoft addressed this month is CVE-2022-26925, a weakness in a central component of Windows security (the “Local Security Authority” process within Windows). CVE-2022-26925 was publicly disclosed prior to today, and Microsoft says it is now actively being exploited in the wild. The flaw affects Windows 7 through 10 and Windows Server 2008 through 2022.

Greg Wiseman, product manager for Rapid7, said Microsoft has rated this vulnerability as important and assigned it a CVSS (danger) score of 8.1 (10 being the worst), although Microsoft notes that the CVSS score can be as high as 9.8 in certain situations.

“This allows attackers to perform a man-in-the-middle attack to force domain controllers to authenticate to the attacker using NTLM authentication,” Wiseman said. “This is very bad news when used in conjunction with an NTLM relay attack, potentially leading to remote code execution. This bug affects all supported versions of Windows, but Domain Controllers should be patched on a priority basis before updating other servers.”

Wiseman said the most recent time Microsoft patched a similar vulnerability — last August in CVE-2021-36942 — it was also being exploited in the wild under the name “PetitPotam.”

“CVE-2021-36942 was so bad it made CISA’s catalog of Known Exploited Vulnerabilities,” Wiseman said.

Seven of the flaws fixed today earned Microsoft’s most-dire “critical” label, which it assigns to vulnerabilities that can be exploited by malware or miscreants to remotely compromise a vulnerable Windows system without any help from the user.

Among those is CVE-2022-26937, which carries a CVSS score of 9.8, and affects services using the Windows Network File System (NFS). Trend Micro’s Zero Day Initiative notes that this bug could allow remote, unauthenticated attackers to execute code in the context of the Network File System (NFS) service on affected systems.

“NFS isn’t on by default, but it’s prevalent in environment where Windows systems are mixed with other OSes such as Linux or Unix,” ZDI’s Dustin Childs wrote. “If this describes your environment, you should definitely test and deploy this patch quickly.”

Once again, this month’s Patch Tuesday is sponsored by Windows Print Spooler, a core Windows service that keeps spooling out the security hits. May’s patches include four fixes for Print Spooler, including two information disclosure and two elevation of privilege flaws.

“All of the flaws are rated as important, and two of the three are considered more likely to be exploited,” said Satnam Narang, staff research engineer at Tenable. “Windows Print Spooler continues to remain a valuable target for attackers since PrintNightmare was disclosed nearly a year ago. Elevation of Privilege flaws in particular should be carefully prioritized, as we’ve seen ransomware groups like Conti favor them as part of its playbook.”

Other Windows components that received patches this month include .NET and Visual Studio, Microsoft Edge (Chromium-based), Microsoft Exchange Server, Office, Windows Hyper-V, Windows Authentication Methods, BitLocker, Remote Desktop Client, and Windows Point-to-Point Tunneling Protocol.

Also today, Adobe issued five security bulletins to address at least 18 flaws in Adobe CloudFusion, Framemaker, InCopy, InDesign, and Adobe Character Animator. Adobe said it is not aware of any exploits in the wild for any of the issues addressed in today’s updates.

For a more granular look at the patches released by Microsoft today and indexed by severity and other metrics, check out the always-useful Patch Tuesday roundup from the SANS Internet Storm Center. And it’s not a bad idea to hold off updating for a few days until Microsoft works out any kinks in the updates: AskWoody.com usually has the skinny on any patches that may be causing problems for Windows users.

As always, please consider backing up your system or at least your important documents and data before applying system updates. And if you run into any problems with these patches, please drop a note about it here in the comments.