Category Archives: Tenable

Adam Barnett, CVE-2024-49112, CVE-2024-49138, Fortra, Immersive Labs, LDAP, Lightweight Directory Access Protocol, Microsoft Patch Tuesday December 2024, Other, Rapid7, Rob Reeves, Tenable, Tyler Reguly, Windows Common Log File System (CLFS) driver

Patch Tuesday, December 2024 Edition

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Microsoft today released updates to plug at least 70 security holes in Windows and Windows software, including one vulnerability that is already being exploited in active attacks.

The zero-day seeing exploitation involves CVE-2024-49138, a security weakness in the Windows Common Log File System (CLFS) driver — used by applications to write transaction logs — that could let an authenticated attacker gain “system” level privileges on a vulnerable Windows device.

The security firm Rapid7 notes there have been a series of zero-day elevation of privilege flaws in CLFS over the past few years.

“Ransomware authors who have abused previous CLFS vulnerabilities will be only too pleased to get their hands on a fresh one,” wrote Adam Barnett, lead software engineer at Rapid7. “Expect more CLFS zero-day vulnerabilities to emerge in the future, at least until Microsoft performs a full replacement of the aging CLFS codebase instead of offering spot fixes for specific flaws.”

Elevation of privilege vulnerabilities accounted for 29% of the 1,009 security bugs Microsoft has patched so far in 2024, according to a year-end tally by Tenable; nearly 40 percent of those bugs were weaknesses that could let attackers run malicious code on the vulnerable device.

Rob Reeves, principal security engineer at Immersive Labs, called special attention to CVE-2024-49112, a remote code execution flaw in the Lightweight Directory Access Protocol (LDAP) service on every version of Windows since Windows 7. CVE-2024-49112 has been assigned a CVSS (badness) score of 9.8 out of 10.

“LDAP is most commonly seen on servers that are Domain Controllers inside a Windows network and LDAP must be exposed to other servers and clients within an enterprise environment for the domain to function,” Reeves said. “Microsoft hasn’t released specific information about the vulnerability at present, but has indicated that the attack complexity is low and authentication is not required.”

Tyler Reguly at the security firm Fortra had a slightly different 2024 patch tally for Microsoft, at 1,088 vulnerabilities, which he said was surprisingly similar to the 1,063 vulnerabilities resolved in 2023 and the 1,119 vulnerabilities resolved in 2022.

“If nothing else, we can say that Microsoft is consistent,” Reguly said. “While it would be nice to see the number of vulnerabilities each year decreasing, at least consistency lets us know what to expect.”

If you’re a Windows end user and your system is not set up to automatically install updates, please take a minute this week to run Windows Update, preferably after backing up your system and/or important data.

System admins should keep an eye on AskWoody.com, which usually has the details if any of the Patch Tuesday fixes are causing problems. In the meantime, if you run into any problems applying this month’s fixes, please drop a note about in the comments below.

Adam Barnett, CVE-2024-49112, CVE-2024-49138, Fortra, Immersive Labs, LDAP, Lightweight Directory Access Protocol, Microsoft Patch Tuesday December 2024, Other, Rapid7, Rob Reeves, Tenable, Tyler Reguly, Windows Common Log File System (CLFS) driver

Patch Tuesday, December 2024 Edition

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Microsoft today released updates to plug at least 70 security holes in Windows and Windows software, including one vulnerability that is already being exploited in active attacks.

The zero-day seeing exploitation involves CVE-2024-49138, a security weakness in the Windows Common Log File System (CLFS) driver — used by applications to write transaction logs — that could let an authenticated attacker gain “system” level privileges on a vulnerable Windows device.

The security firm Rapid7 notes there have been a series of zero-day elevation of privilege flaws in CLFS over the past few years.

“Ransomware authors who have abused previous CLFS vulnerabilities will be only too pleased to get their hands on a fresh one,” wrote Adam Barnett, lead software engineer at Rapid7. “Expect more CLFS zero-day vulnerabilities to emerge in the future, at least until Microsoft performs a full replacement of the aging CLFS codebase instead of offering spot fixes for specific flaws.”

Elevation of privilege vulnerabilities accounted for 29% of the 1,009 security bugs Microsoft has patched so far in 2024, according to a year-end tally by Tenable; nearly 40 percent of those bugs were weaknesses that could let attackers run malicious code on the vulnerable device.

Rob Reeves, principal security engineer at Immersive Labs, called special attention to CVE-2024-49112, a remote code execution flaw in the Lightweight Directory Access Protocol (LDAP) service on every version of Windows since Windows 7. CVE-2024-49112 has been assigned a CVSS (badness) score of 9.8 out of 10.

“LDAP is most commonly seen on servers that are Domain Controllers inside a Windows network and LDAP must be exposed to other servers and clients within an enterprise environment for the domain to function,” Reeves said. “Microsoft hasn’t released specific information about the vulnerability at present, but has indicated that the attack complexity is low and authentication is not required.”

Tyler Reguly at the security firm Fortra had a slightly different 2024 patch tally for Microsoft, at 1,088 vulnerabilities, which he said was surprisingly similar to the 1,063 vulnerabilities resolved in 2023 and the 1,119 vulnerabilities resolved in 2022.

“If nothing else, we can say that Microsoft is consistent,” Reguly said. “While it would be nice to see the number of vulnerabilities each year decreasing, at least consistency lets us know what to expect.”

If you’re a Windows end user and your system is not set up to automatically install updates, please take a minute this week to run Windows Update, preferably after backing up your system and/or important data.

System admins should keep an eye on AskWoody.com, which usually has the details if any of the Patch Tuesday fixes are causing problems. In the meantime, if you run into any problems applying this month’s fixes, please drop a note about in the comments below.

CVE-2024-43451, CVE-2024-43602, CVE-2024-49019, CVE-2024-49039, CVE-2024-49040, Google TAG, Microsoft Patch Tuesday November 2024, Satnam Narang, Security Tools, Tenable, Time to Patch

Microsoft Patch Tuesday, November 2024 Edition

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Microsoft today released updates to plug at least 89 security holes in its Windows operating systems and other software. November’s patch batch includes fixes for two zero-day vulnerabilities that are already being exploited by attackers, as well as two other flaws that were publicly disclosed prior to today.

The zero-day flaw tracked as CVE-2024-49039 is a bug in the Windows Task Scheduler that allows an attacker to increase their privileges on a Windows machine. Microsoft credits Google’s Threat Analysis Group with reporting the flaw.

The second bug fixed this month that is already seeing in-the-wild exploitation is CVE-2024-43451, a spoofing flaw that could reveal Net-NTLMv2 hashes, which are used for authentication in Windows environments.

Satnam Narang, senior staff research engineer at Tenable, says the danger with stolen NTLM hashes is that they enable so-called “pass-the-hash” attacks, which let an attacker masquerade as a legitimate user without ever having to log in or know the user’s password. Narang notes that CVE-2024-43451 is the third NTLM zero-day so far this year.

“Attackers continue to be adamant about discovering and exploiting zero-day vulnerabilities that can disclose NTLMv2 hashes, as they can be used to authenticate to systems and potentially move laterally within a network to access other systems,” Narang said.

The two other publicly disclosed weaknesses Microsoft patched this month are CVE-2024-49019, an elevation of privilege flaw in Active Directory Certificate Services (AD CS); and CVE-2024-49040, a spoofing vulnerability in Microsoft Exchange Server.

Ben McCarthy, lead cybersecurity engineer at Immersive Labs, called special attention to CVE-2024-43602, a remote code execution vulnerability in Windows Kerberos, the authentication protocol that is heavily used in Windows domain networks.

“This is one of the most threatening CVEs from this patch release,” McCarthy said. “Windows domains are used in the majority of enterprise networks, and by taking advantage of a cryptographic protocol vulnerability, an attacker can perform privileged acts on a remote machine within the network, potentially giving them eventual access to the domain controller, which is the goal for many attackers when attacking a domain.”

McCarthy also pointed to CVE-2024-43498, a remote code execution flaw in .NET and Visual Studio that could be used to install malware. This bug has earned a CVSS severity rating of 9.8 (10 is the worst).

Finally, at least 29 of the updates released today tackle memory-related security issues involving SQL server, each of which earned a threat score of 8.8. Any one of these bugs could be used to install malware if an authenticated user connects to a malicious or hacked SQL database server.

For a more detailed breakdown of today’s patches from Microsoft, check out the SANS Internet Storm Center’s list. For administrators in charge of managing larger Windows environments, it pays to keep an eye on Askwoody.com, which frequently points out when specific Microsoft updates are creating problems for a number of users.

As always, if you experience any problems applying any of these updates, consider dropping a note about it in the comments; chances are excellent that someone else reading here has experienced the same issue, and maybe even has found a solution.

.NET, adobe, Adobe Framemaker, Adobe Substance 3D Painter, Animate, Apple, Azure, Commerce, CVE-2024-43572, CVE-2024-43573, Dimension, Elastic Security Labs, GrimResource, Immersive Labs, InCopy, InDesign, Latest Warnings, Lightroom, macOS 15, MSHTML, Nikolas Cemerikic, Office, OpenSSH for Windows; Power BI; Windows Hyper-V; Windows Mobile Broadband, Satnam Narang, Security Tools, Sequoia, Substance 3D Stager, Tenable, Time to Patch, Visual Studio

Patch Tuesday, October 2024 Edition

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Microsoft today released security updates to fix at least 117 security holes in Windows computers and other software, including two vulnerabilities that are already seeing active attacks. Also, Adobe plugged 52 security holes across a range of products, and Apple has addressed a bug in its new macOS 15 “Sequoia” update that broke many cybersecurity tools.

One of the zero-day flaws — CVE-2024-43573 — stems from a security weakness in MSHTML, the proprietary engine of Microsoft’s Internet Explorer web browser. If that sounds familiar it’s because this is the fourth MSHTML vulnerability found to be exploited in the wild so far in 2024.

Nikolas Cemerikic, a cybersecurity engineer at Immersive Labs, said the vulnerability allows an attacker to trick users into viewing malicious web content, which could appear legitimate thanks to the way Windows handles certain web elements.

“Once a user is deceived into interacting with this content (typically through phishing attacks), the attacker can potentially gain unauthorized access to sensitive information or manipulate web-based services,” he said.

Cemerikic noted that while Internet Explorer is being retired on many platforms, its underlying MSHTML technology remains active and vulnerable.

“This creates a risk for employees using these older systems as part of their everyday work, especially if they are accessing sensitive data or performing financial transactions online,” he said.

Probably the more serious zero-day this month is CVE-2024-43572, a code execution bug in the Microsoft Management Console, a component of Windows that gives system administrators a way to configure and monitor the system.

Satnam Narang, senior staff research engineer at Tenable, observed that the patch for CVE-2024-43572 arrived a few months after researchers at Elastic Security Labs disclosed an attack technique called GrimResource that leveraged an old cross-site scripting (XSS) vulnerability combined with a specially crafted Microsoft Saved Console (MSC) file to gain code execution privileges.

“Although Microsoft patched a different MMC vulnerability in September (CVE-2024-38259) that was neither exploited in the wild nor publicly disclosed,” Narang said. “Since the discovery of CVE-2024-43572, Microsoft now prevents untrusted MSC files from being opened on a system.”

Microsoft also patched Office, Azure, .NET, OpenSSH for Windows; Power BI; Windows Hyper-V; Windows Mobile Broadband, and Visual Studio. As usual, the SANS Internet Storm Center has a list of all Microsoft patches released today, indexed by severity and exploitability.

Late last month, Apple rolled out macOS 15, an operating system update called Sequoia that broke the functionality of security tools made by a number of vendors, including CrowdStrike, SentinelOne and Microsoft. On Oct. 7, Apple pushed an update to Sequoia users that addresses these compatibility issues.

Finally, Adobe has released security updates to plug a total of 52 vulnerabilities in a range of software, including Adobe Substance 3D Painter, Commerce, Dimension, Animate, Lightroom, InCopy, InDesign, Substance 3D Stager, and Adobe FrameMaker.

Please consider backing up important data before applying any updates. Zero-days aside, there’s generally little harm in waiting a few days to apply any pending patches, because not infrequently a security update introduces stability or compatibility issues. AskWoody.com usually has the skinny on any problematic patches.

And as always, if you run into any glitches after installing patches, leave a note in the comments; chances are someone else is stuck with the same issue and may have even found a solution.

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Patch Tuesday, May 2024 Edition

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Microsoft today released updates to fix more than 60 security holes in Windows computers and supported software, including two “zero-day” vulnerabilities in Windows that are already being exploited in active attacks. There are also important security patches available for macOS and Adobe users, and for the Chrome Web browser, which just patched its own zero-day flaw.

First, the zero-days. CVE-2024-30051 is an “elevation of privilege” bug in a core Windows library. Satnam Narang at Tenable said this flaw is being used as part of post-compromise activity to elevate privileges as a local attacker.

“CVE-2024-30051 is used to gain initial access into a target environment and requires the use of social engineering tactics via email, social media or instant messaging to convince a target to open a specially crafted document file,” Narang said. “Once exploited, the attacker can bypass OLE mitigations in Microsoft 365 and Microsoft Office, which are security features designed to protect end users from malicious files.”

CVE-2024-30040 is a security feature bypass in MSHTML, a component that is deeply tied to the default Web browser on Windows systems. Microsoft’s advisory on this flaw is fairly sparse, but Kevin Breen from Immersive Labs said this vulnerability also affects Office 365 and Microsoft Office applications.

“Very little information is provided and the short description is painfully obtuse,” Breen said of Microsoft’s advisory on CVE-2024-30040.

Meanwhile, Kaspersky Lab, one of two companies credited with reporting exploitation of CVE-2024-30040 to Microsoft, has published a fascinating writeup on how they discovered the exploit in a file shared with Virustotal.com.

Kaspersky said it has since seen the exploit used together with QakBot and other malware. Emerging in 2007 as a banking trojan, QakBot (a.k.a. Qbot and Pinkslipbot) has morphed into an advanced malware strain now used by multiple cybercriminal groups to prepare newly compromised networks for ransomware infestations.

The only vulnerability fixed this month that earned Microsoft’s most-dire “critical” rating is CVE-2024-30044, a flaw in Sharepoint that Microsoft said is likely to be exploited. Tenable’s Narang notes that exploitation of this bug requires an attacker to be authenticated to a vulnerable SharePoint Server with Site Owner permissions (or higher) first and to take additional steps in order to exploit this flaw, which makes this flaw less likely to be widely exploited as most attackers follow the path of least resistance.

Five days ago, Google released a security update for Chrome that fixes a zero-day in the popular browser. Chrome usually auto-downloads any available updates, but it still may require a complete restart of the browser to install them. If you use Chrome and see a “Relaunch to update” message in the upper right corner of the browser, it’s time to restart.

Apple has just shipped macOS Sonoma 14.5 update, which includes nearly two dozen security patches. To ensure your Mac is up-to-date, go to System Settings, General tab, then Software Update and follow any prompts.

Finally, Adobe has critical security patches available for a range of products, including Acrobat, Reader, Illustrator, Adobe Substance 3D Painter, Adobe Aero, Adobe Animate and Adobe Framemaker.

Regardless of whether you use a Mac or Windows system (or something else), it’s always a good idea to backup your data and or system before applying any security updates. For a closer look at the individual fixes released by Microsoft today, check out the complete list over at the SANS Internet Storm Center. Anyone in charge of maintaining Windows systems in an enterprise environment should keep an eye on askwoody.com, which usually has the scoop on any wonky Windows patches.

Acrobat, Adobe Aero, Adobe Animate, Adobe Framemaker, Adobe Substance 3D Painter, CVE-2024-30040, CVE-2024-30044, CVE-2024-30051, Google Chrome, Illustrator, Immersive Labs, Kevin Breen, macOS Sonoma 14.5 update, MSHTML, Qakbot, reader, Satnam Narang, Sharepoint, Tenable, Time to Patch

Patch Tuesday, May 2024 Edition

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Microsoft today released updates to fix more than 60 security holes in Windows computers and supported software, including two “zero-day” vulnerabilities in Windows that are already being exploited in active attacks. There are also important security patches available for macOS and Adobe users, and for the Chrome Web browser, which just patched its own zero-day flaw.

First, the zero-days. CVE-2024-30051 is an “elevation of privilege” bug in a core Windows library. Satnam Narang at Tenable said this flaw is being used as part of post-compromise activity to elevate privileges as a local attacker.

“CVE-2024-30051 is used to gain initial access into a target environment and requires the use of social engineering tactics via email, social media or instant messaging to convince a target to open a specially crafted document file,” Narang said. “Once exploited, the attacker can bypass OLE mitigations in Microsoft 365 and Microsoft Office, which are security features designed to protect end users from malicious files.”

CVE-2024-30040 is a security feature bypass in MSHTML, a component that is deeply tied to the default Web browser on Windows systems. Microsoft’s advisory on this flaw is fairly sparse, but Kevin Breen from Immersive Labs said this vulnerability also affects Office 365 and Microsoft Office applications.

“Very little information is provided and the short description is painfully obtuse,” Breen said of Microsoft’s advisory on CVE-2024-30040.

Meanwhile, Kaspersky Lab, one of two companies credited with reporting exploitation of CVE-2024-30040 to Microsoft, has published a fascinating writeup on how they discovered the exploit in a file shared with Virustotal.com.

Kaspersky said it has since seen the exploit used together with QakBot and other malware. Emerging in 2007 as a banking trojan, QakBot (a.k.a. Qbot and Pinkslipbot) has morphed into an advanced malware strain now used by multiple cybercriminal groups to prepare newly compromised networks for ransomware infestations.

The only vulnerability fixed this month that earned Microsoft’s most-dire “critical” rating is CVE-2024-30044, a flaw in Sharepoint that Microsoft said is likely to be exploited. Tenable’s Narang notes that exploitation of this bug requires an attacker to be authenticated to a vulnerable SharePoint Server with Site Owner permissions (or higher) first and to take additional steps in order to exploit this flaw, which makes this flaw less likely to be widely exploited as most attackers follow the path of least resistance.

Five days ago, Google released a security update for Chrome that fixes a zero-day in the popular browser. Chrome usually auto-downloads any available updates, but it still may require a complete restart of the browser to install them. If you use Chrome and see a “Relaunch to update” message in the upper right corner of the browser, it’s time to restart.

Apple has just shipped macOS Sonoma 14.5 update, which includes nearly two dozen security patches. To ensure your Mac is up-to-date, go to System Settings, General tab, then Software Update and follow any prompts.

Finally, Adobe has critical security patches available for a range of products, including Acrobat, Reader, Illustrator, Adobe Substance 3D Painter, Adobe Aero, Adobe Animate and Adobe Framemaker.

Regardless of whether you use a Mac or Windows system (or something else), it’s always a good idea to backup your data and or system before applying any security updates. For a closer look at the individual fixes released by Microsoft today, check out the complete list over at the SANS Internet Storm Center. Anyone in charge of maintaining Windows systems in an enterprise environment should keep an eye on askwoody.com, which usually has the scoop on any wonky Windows patches.

Adobe Acrobat, Adobe AI Assistant, Adobe Animate, Adobe Bridge, Adobe Experience Manager, Adobe Premier Pro, Automox, ColdFusion 2023 and 2021, CVE-2024-21334, CVE-2024-21390, CVE-2024-21433, CVE-2024-21435, CVE-2024-21437, CVE-2024-23225, CVE-2024-23296, CVE-2024-26170, CVE-2024-26182, Immersive Labs, iOS 16.7.6, iOS 17.4, iPadOS 17.4, Jason Kitka, Kevin Breen, Lightroom, Microsoft Authenticator, Microsoft Azure, Satnam Narang, Security Tools, Tenable, Time to Patch

Patch Tuesday, March 2024 Edition

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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 updates 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 (1o 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 Kevin Breen, senior director of threat research 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.

Adam Barnett, CVE-2024-21351, CVE-2024-21410, CVE-2024-21412, CVE-2024-21413, Immersive Labs, Kevin Breen, Latest Warnings, Microsoft office, Patch Tuesday February 2024, Rapid7, Satnam Narang, Security Tools, Tenable, Time to Patch, trend micro, Windows SmartScreen

Fat Patch Tuesday, February 2024 Edition

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Microsoft Corp. today pushed software updates to plug more than 70 security holes in its Windows operating systems and related products, including two zero-day vulnerabilities that are already being exploited in active attacks.

Top of the heap on this Fat Patch Tuesday is CVE-2024-21412, a “security feature bypass” in the way Windows handles Internet Shortcut Files that Microsoft says is being targeted in active exploits. Redmond’s advisory for this bug says an attacker would need to convince or trick a user into opening a malicious shortcut file.

Researchers at Trend Micro have tied the ongoing exploitation of CVE-2024-21412 to an advanced persistent threat group dubbed “Water Hydra,” which they say has being using the vulnerability to execute a malicious Microsoft Installer File (.msi) that in turn unloads a remote access trojan (RAT) onto infected Windows systems.

The other zero-day flaw is CVE-2024-21351, another security feature bypass — this one in the built-in Windows SmartScreen component that tries to screen out potentially malicious files downloaded from the Web. Kevin Breen at Immersive Labs says it’s important to note that this vulnerability alone is not enough for an attacker to compromise a user’s workstation, and instead would likely be used in conjunction with something like a spear phishing attack that delivers a malicious file.

Satnam Narang, senior staff research engineer at Tenable, said this is the fifth vulnerability in Windows SmartScreen patched since 2022 and all five have been exploited in the wild as zero-days. They include CVE-2022-44698 in December 2022, CVE-2023-24880 in March 2023, CVE-2023-32049 in July 2023 and CVE-2023-36025 in November 2023.

Narang called special attention to CVE-2024-21410, an “elevation of privilege” bug in Microsoft Exchange Server that Microsoft says is likely to be exploited by attackers. Attacks on this flaw would lead to the disclosure of NTLM hashes, which could be leveraged as part of an NTLM relay or “pass the hash” attack, which lets an attacker masquerade as a legitimate user without ever having to log in.

“We know that flaws that can disclose sensitive information like NTLM hashes are very valuable to attackers,” Narang said. “A Russian-based threat actor leveraged a similar vulnerability to carry out attacks – CVE-2023-23397 is an Elevation of Privilege vulnerability in Microsoft Outlook patched in March 2023.”

Microsoft notes that prior to its Exchange Server 2019 Cumulative Update 14 (CU14), a security feature called Extended Protection for Authentication (EPA), which provides NTLM credential relay protections, was not enabled by default.

“Going forward, CU14 enables this by default on Exchange servers, which is why it is important to upgrade,” Narang said.

Rapid7’s lead software engineer Adam Barnett highlighted CVE-2024-21413, a critical remote code execution bug in Microsoft Office that could be exploited just by viewing a specially-crafted message in the Outlook Preview pane.

“Microsoft Office typically shields users from a variety of attacks by opening files with Mark of the Web in Protected View, which means Office will render the document without fetching potentially malicious external resources,” Barnett said. “CVE-2024-21413 is a critical RCE vulnerability in Office which allows an attacker to cause a file to open in editing mode as though the user had agreed to trust the file.”

Barnett stressed that administrators responsible for Office 2016 installations who apply patches outside of Microsoft Update should note the advisory lists no fewer than five separate patches which must be installed to achieve remediation of CVE-2024-21413; individual update knowledge base (KB) articles further note that partially-patched Office installations will be blocked from starting until the correct combination of patches has been installed.

It’s a good idea for Windows end-users to stay current with security updates from Microsoft, which can quickly pile up otherwise. That doesn’t mean you have to install them on Patch Tuesday. Indeed, waiting a day or three before updating is a sane response, given that sometimes updates go awry and usually within a few days Microsoft has fixed any issues with its patches. It’s also smart to back up your data and/or image your Windows drive before applying new updates.

For a more detailed breakdown of the individual flaws addressed by Microsoft today, check out the SANS Internet Storm Center’s list. For those admins responsible for maintaining larger Windows environments, it often pays to keep an eye on Askwoody.com, which frequently points out when specific Microsoft updates are creating problems for a number of users.

CVE-2023-35628, CVE-2023-35636, CVE-2023-35641, Immersive Labs, Kevin Breen, Latest Warnings, Microsoft Patch Tuesday December 2023, Satnam Narang, Tenable, The Coming Storm, Time to Patch

Microsoft Patch Tuesday, December 2023 Edition

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The final Patch Tuesday of 2023 is upon us, with Microsoft Corp. today releasing fixes for a relatively small number of security holes in its Windows operating systems and other software. Even more unusual, there are no known “zero-day” threats targeting any of the vulnerabilities in December’s patch batch. Still, four of the updates pushed out today address “critical” vulnerabilities that Microsoft says can be exploited by malware or malcontents to seize complete control over a vulnerable Windows device with little or no help from users.

Among the critical bugs quashed this month is CVE-2023-35628, a weakness present in Windows 10 and later versions, as well as Microsoft Server 2008 and later. Kevin Breen, senior director of threat research at Immersive Labs, said the flaw affects MSHTML, a core component of Windows that is used to render browser-based content. Breen notes that MSHTML also can be found in a number of Microsoft applications, including Office, Outlook, Skype and Teams.

“In the worst-case scenario, Microsoft suggests that simply receiving an email would be enough to trigger the vulnerability and give an attacker code execution on the target machine without any user interaction like opening or interacting with the contents,” Breen said.

Another critical flaw that probably deserves priority patching is CVE-2023-35641, a remote code execution weakness in a built-in Windows feature called the Internet Connection Sharing (ICS) service that lets multiple devices share an Internet connection. While CVE-2023-35641 earned a high vulnerability severity score (a CVSS rating of 8.8), the threat from this flaw may be limited somewhat because an attacker would need to be on the same network as the target. Also, while ICS is present in all versions of Windows since Windows 7, it is not on by default (although some applications may turn it on).

Satnam Narang, senior staff research engineer at Tenable, notes that a number of the non-critical patches released today were identified by Microsoft as “more likely to be exploited.” For example, CVE-2023-35636, which Microsoft says is an information disclosure vulnerability in Outlook. An attacker could exploit this flaw by convincing a potential victim to open a specially crafted file delivered via email or hosted on a malicious website.

Narang said what makes this one stand out is that exploitation of this flaw would lead to the disclosure of NTLM hashes, which could be leveraged as part of an NTLM relay or “pass the hash” attack, which lets an attacker masquerade as a legitimate user without ever having to log in.

”It is reminiscent of CVE-2023-23397, an elevation of privilege vulnerability in Microsoft Outlook that was exploited in the wild as a zero day and patched in the March 2023 Patch Tuesday release,” Narang said. “However, unlike CVE-2023-23397, CVE-2023-35636 is not exploitable via Microsoft’s Preview Pane, which lowers the severity of this flaw.”

As usual, the SANS Internet Storm Center has a good roundup on all of the patches released today and indexed by severity. Windows users, 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 difficulties as a result of these patches.

adobe, CVE-2023-21709, CVE-2023-36884, CVE-2023-36910, CVE-2023-38180, Immersive Labs, Microsoft, Microsoft Patch Tuesday August 2023, Nikolas Cemerikic, Satnam Narang, Security Tools, Tenable, Time to Patch

Microsoft Patch Tuesday, August 2023 Edition

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Microsoft Corp. today issued software updates to plug more than 70 security holes in its Windows operating systems and related products, including multiple zero-day vulnerabilities currently being exploited in the wild.

Six of the flaws fixed today earned Microsoft’s “critical” rating, meaning malware or miscreants could use them to install software on a vulnerable Windows system without any help from users.

Last month, Microsoft acknowledged a series of zero-day vulnerabilities in a variety of Microsoft products that were discovered and exploited in-the-wild attacks. They were assigned a single placeholder designation of CVE-2023-36884.

Satnam Narang, senior staff research engineer at Tenable, said the August patch batch addresses CVE-2023-36884, which involves bypassing the Windows Search Security feature.

“Microsoft also released ADV230003, a defense-in-depth update designed to stop the attack chain associated that leads to the exploitation of this CVE,” Narang said. “Given that this has already been successfully exploited in the wild as a zero-day, organizations should prioritize patching this vulnerability and applying the defense-in-depth update as soon as possible.”

Redmond patched another flaw that is already seeing active attacks — CVE-2023-38180 — a weakness in .NET and Visual Studio that leads to a denial-of-service condition on vulnerable servers.

“Although the attacker would need to be on the same network as the target system, this vulnerability does not require the attacker to have acquired user privileges,” on the target system, wrote Nikolas Cemerikic, cyber security engineer at Immersive Labs.

Narang said the software giant also patched six vulnerabilities in Microsoft Exchange Server, including CVE-2023-21709, an elevation of privilege flaw that was assigned a CVSSv3 (threat) score of 9.8 out of a possible 10, even though Microsoft rates it as an important flaw, not critical.

“An unauthenticated attacker could exploit this vulnerability by conducting a brute-force attack against valid user accounts,” Narang said. “Despite the high rating, the belief is that brute-force attacks won’t be successful against accounts with strong passwords. However, if weak passwords are in use, this would make brute-force attempts more successful. The remaining five vulnerabilities range from a spoofing flaw and multiple remote code execution bugs, though the most severe of the bunch also require credentials for a valid account.”

Experts at security firm Automox called attention to CVE-2023-36910, a remote code execution bug in the Microsoft Message Queuing service that can be exploited remotely and without privileges to execute code on vulnerable Windows 10, 11 and Server 2008-2022 systems. Microsoft says it considers this vulnerability “less likely” to be exploited, and Automox says while the message queuing service is not enabled by default in Windows and is less common today, any device with it enabled is at critical risk.

Separately, Adobe has issued a critical security update for Acrobat and Reader that resolves at least 30 security vulnerabilities in those products. Adobe said it is not aware of any exploits in the wild targeting these flaws. The company also issued security updates for Adobe Commerce and Adobe Dimension.

If you experience glitches or problems installing any of these patches this month, please consider leaving a comment about it below; there’s a fair chance other readers have experienced the same and may chime in here with useful tips.

Additional reading:

-SANS Internet Storm Center listing of each Microsoft vulnerability patched today, indexed by severity and affected component.

–AskWoody.com, which keeps tabs on any developing problems related to the availability or installation of these updates.