April’s Patch Tuesday Brings Record Number of Fixes

If only Patch Tuesdays came around infrequently — like total solar eclipse rare — instead of just creeping up on us each month like The Man in the Moon. Although to be fair, it would be tough for Microsoft to eclipse the number of vulnerabilities fixed in this month’s patch batch — a record 147 flaws in Windows and related software.

Yes, you read that right. Microsoft today released updates to address 147 security holes in Windows, Office, Azure, .NET Framework, Visual Studio, SQL Server, DNS Server, Windows Defender, Bitlocker, and Windows Secure Boot.

“This is the largest release from Microsoft this year and the largest since at least 2017,” said Dustin Childs, from Trend Micro’s Zero Day Initiative (ZDI). “As far as I can tell, it’s the largest Patch Tuesday release from Microsoft of all time.”

Tempering the sheer volume of this month’s patches is the middling severity of many of the bugs. Only three of April’s vulnerabilities earned Microsoft’s most-dire “critical” rating, meaning they can be abused by malware or malcontents to take remote control over unpatched systems with no help from users.

Most of the flaws that Microsoft deems “more likely to be exploited” this month are marked as “important,” which usually involve bugs that require a bit more user interaction (social engineering) but which nevertheless can result in system security bypass, compromise, and the theft of critical assets.

Ben McCarthy, lead cyber security engineer at Immersive Labs called attention to CVE-2024-20670, an Outlook for Windows spoofing vulnerability described as being easy to exploit. It involves convincing a user to click on a malicious link in an email, which can then steal the user’s password hash and authenticate as the user in another Microsoft service.

Another interesting bug McCarthy pointed to is CVE-2024-29063, which involves hard-coded credentials in Azure’s search backend infrastructure that could be gleaned by taking advantage of Azure AI search.

“This along with many other AI attacks in recent news shows a potential new attack surface that we are just learning how to mitigate against,” McCarthy said. “Microsoft has updated their backend and notified any customers who have been affected by the credential leakage.”

CVE-2024-29988 is a weakness that allows attackers to bypass Windows SmartScreen, a technology Microsoft designed to provide additional protections for end users against phishing and malware attacks. Childs said one of ZDI’s researchers found this vulnerability being exploited in the wild, although Microsoft doesn’t currently list CVE-2024-29988 as being exploited.

“I would treat this as in the wild until Microsoft clarifies,” Childs said. “The bug itself acts much like CVE-2024-21412 – a [zero-day threat from February] that bypassed the Mark of the Web feature and allows malware to execute on a target system. Threat actors are sending exploits in a zipped file to evade EDR/NDR detection and then using this bug (and others) to bypass Mark of the Web.”

Update, 7:46 p.m. ET: A previous version of this story said there were no zero-day vulnerabilities fixed this month. BleepingComputer reports that Microsoft has since confirmed that there are actually two zero-days. One is the flaw Childs just mentioned (CVE-2024-21412), and the other is CVE-2024-26234, described as a “proxy driver spoofing” weakness.

Satnam Narang at Tenable notes that this month’s release includes fixes for two dozen flaws in Windows Secure Boot, the majority of which are considered “Exploitation Less Likely” according to Microsoft.

“However, the last time Microsoft patched a flaw in Windows Secure Boot in May 2023 had a notable impact as it was exploited in the wild and linked to the BlackLotus UEFI bootkit, which was sold on dark web forums for $5,000,” Narang said. “BlackLotus can bypass functionality called secure boot, which is designed to block malware from being able to load when booting up. While none of these Secure Boot vulnerabilities addressed this month were exploited in the wild, they serve as a reminder that flaws in Secure Boot persist, and we could see more malicious activity related to Secure Boot in the future.”

For links to individual security advisories indexed by severity, check out ZDI’s blog and the Patch Tuesday post from the SANS Internet Storm Center. Please consider backing up your data or your drive before updating, and drop a note in the comments here if you experience any issues applying these fixes.

Adobe today released nine patches tackling at least two dozen vulnerabilities in a range of software products, including Adobe After Effects, Photoshop, Commerce, InDesign, Experience Manager, Media Encoder, Bridge, Illustrator, and Adobe Animate.

KrebsOnSecurity needs to correct the record on a point mentioned at the end of March’s “Fat Patch Tuesday” post, which looked at new AI capabilities built into Adobe Acrobat that are turned on by default. Adobe has since clarified that its apps won’t use AI to auto-scan your documents, as the original language in its FAQ suggested.

“In practice, no document scanning or analysis occurs unless a user actively engages with the AI features by agreeing to the terms, opening a document, and selecting the AI Assistant or generative summary buttons for that specific document,” Adobe said earlier this month.

Patch Tuesday, March 2024 Edition

Apple and Microsoft recently released software updates to fix dozens of security holes in their operating systems. Microsoft today patched at least 60 vulnerabilities in its Windows OS. Meanwhile, Apple’s new macOS Sonoma addresses at least 68 security weaknesses, and its latest update for iOS fixes two zero-day flaws.

Last week, Apple pushed out an urgent software update to its flagship iOS platform, warning that there were at least two zero-day exploits for vulnerabilities being used in the wild (CVE-2024-23225 and CVE-2024-23296). The security updates are available in iOS 17.4, iPadOS 17.4, and iOS 16.7.6.

Apple’s macOS Sonoma 14.4 Security Update addresses dozens of security issues. Jason Kitka, chief information security officer at Automox, said the vulnerabilities patched in this update often stem from memory safety issues, a concern that has led to a broader industry conversation about the adoption of memory-safe programming languages [full disclosure: Automox is an advertiser on this site].

On Feb. 26, 2024, the Biden administration issued a report that calls for greater adoption of memory-safe programming languages. On Mar. 4, 2024, Google published Secure by Design, which lays out the company’s perspective on memory safety risks.

Mercifully, there do not appear to be any zero-day threats hounding Windows users this month (at least not yet). Satnam Narang, senior staff research engineer at Tenable, notes that of the 60 CVEs in this month’s Patch Tuesday release, only six are considered “more likely to be exploited” according to Microsoft.

Those more likely to be exploited bugs are mostly “elevation of privilege vulnerabilities” including CVE-2024-26182 (Windows Kernel), CVE-2024-26170 (Windows Composite Image File System (CimFS), CVE-2024-21437 (Windows Graphics Component), and CVE-2024-21433 (Windows Print Spooler).

Narang highlighted CVE-2024-21390 as a particularly interesting vulnerability in this month’s Patch Tuesday release, which is an elevation of privilege flaw in Microsoft Authenticator, the software giant’s app for multi-factor authentication. Narang said a prerequisite for an attacker to exploit this flaw is to already have a presence on the device either through malware or a malicious application.

“If a victim has closed and re-opened the Microsoft Authenticator app, an attacker could obtain multi-factor authentication codes and modify or delete accounts from the app,” Narang said. “Having access to a target device is bad enough as they can monitor keystrokes, steal data and redirect users to phishing websites, but if the goal is to remain stealth, they could maintain this access and steal multi-factor authentication codes in order to login to sensitive accounts, steal data or hijack the accounts altogether by changing passwords and replacing the multi-factor authentication device, effectively locking the user out of their accounts.”

CVE-2024-21334 earned a CVSS (danger) score of 9.8 (10 is the worst), and it concerns a weakness in Open Management Infrastructure (OMI), a Linux-based cloud infrastructure in Microsoft Azure. Microsoft says attackers could connect to OMI instances over the Internet without authentication, and then send specially crafted data packets to gain remote code execution on the host device.

CVE-2024-21435 is a CVSS 8.8 vulnerability in Windows OLE, which acts as a kind of backbone for a great deal of communication between applications that people use every day on Windows, said Ben McCarthy, lead cybersecurity engineer at Immersive Labs.

“With this vulnerability, there is an exploit that allows remote code execution, the attacker needs to trick a user into opening a document, this document will exploit the OLE engine to download a malicious DLL to gain code execution on the system,” Breen explained. “The attack complexity has been described as low meaning there is less of a barrier to entry for attackers.”

A full list of the vulnerabilities addressed by Microsoft this month is available at the SANS Internet Storm Center, which breaks down the updates by severity and urgency.

Finally, Adobe today issued security updates that fix dozens of security holes in a wide range of products, including Adobe Experience Manager, Adobe Premiere Pro, ColdFusion 2023 and 2021, Adobe Bridge, Lightroom, and Adobe Animate. Adobe said it is not aware of active exploitation against any of the flaws.

By the way, Adobe recently enrolled all of its Acrobat users into a “new generative AI feature” that scans the contents of your PDFs so that its new “AI Assistant” can  “understand your questions and provide responses based on the content of your PDF file.” Adobe provides instructions on how to disable the AI features and opt out here.

Microsoft Patch Tuesday, June 2022 Edition

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.