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Microsoft on Tuesday released software updates to fix at least 70 vulnerabilities in Windows and related products, including five zero-day flaws that are already seeing active exploitation. Adding to the sense of urgency with this month’s patch batch from Redmond are fixes for two other weaknesses that now have public proof-of-concept exploits available.
Microsoft and several security firms have disclosed that attackers are exploiting a pair of bugs in the Windows Common Log File System (CLFS) driver that allow attackers to elevate their privileges on a vulnerable device. The Windows CLFS is a critical Windows component responsible for logging services, and is widely used by Windows system services and third-party applications for logging. Tracked as CVE-2025-32701 & CVE-2025-32706, these flaws are present in all supported versions of Windows 10 and 11, as well as their server versions.
Kev Breen, senior director of threat research at Immersive Labs, said privilege escalation bugs assume an attacker already has initial access to a compromised host, typically through a phishing attack or by using stolen credentials. But if that access already exists, Breen said, attackers can gain access to the much more powerful Windows SYSTEM account, which can disable security tooling or even gain domain administration level permissions using credential harvesting tools.
“The patch notes don’t provide technical details on how this is being exploited, and no Indicators of Compromise (IOCs) are shared, meaning the only mitigation security teams have is to apply these patches immediately,” he said. “The average time from public disclosure to exploitation at scale is less than five days, with threat actors, ransomware groups, and affiliates quick to leverage these vulnerabilities.”
Two other zero-days patched by Microsoft today also were elevation of privilege flaws: CVE-2025-32709, which concerns afd.sys, the Windows Ancillary Function Driver that enables Windows applications to connect to the Internet; and CVE-2025-30400, a weakness in the Desktop Window Manager (DWM) library for Windows. As Adam Barnett at Rapid7 notes, tomorrow marks the one-year anniversary of CVE-2024-30051, a previous zero-day elevation of privilege vulnerability in this same DWM component.
The fifth zero-day patched today is CVE-2025-30397, a flaw in the Microsoft Scripting Engine, a key component used by Internet Explorer and Internet Explorer mode in Microsoft Edge.
Chris Goettl at Ivanti points out that the Windows 11 and Server 2025 updates include some new AI features that carry a lot of baggage and weigh in at around 4 gigabytes. Said baggage includes new artificial intelligence (AI) capabilities, including the controversial Recall feature, which constantly takes screenshots of what users are doing on Windows CoPilot-enabled computers.
Microsoft went back to the drawing board on Recall after a fountain of negative feedback from security experts, who warned it would present an attractive target and a potential gold mine for attackers. Microsoft appears to have made some efforts to prevent Recall from scooping up sensitive financial information, but privacy and security concerns still linger. Former Microsoftie Kevin Beaumont has a good teardown on Microsoft’s updates to Recall.
In any case, windowslatest.com reports that Windows 11 version 24H2 shows up ready for downloads, even if you don’t want it.
“It will now show up for ‘download and install’ automatically if you go to Settings > Windows Update and click Check for updates, but only when your device does not have a compatibility hold,” the publication reported. “Even if you don’t check for updates, Windows 11 24H2 will automatically download at some point.”
Apple users likely have their own patching to do. On May 12 Apple released security updates to fix at least 30 vulnerabilities in iOS and iPadOS (the updated version is 18.5). TechCrunch writes that iOS 18.5 also expands emergency satellite capabilities to iPhone 13 owners for the first time (previously it was only available on iPhone 14 or later).
Apple also released updates for macOS Sequoia, macOS Sonoma, macOS Ventura, WatchOS, tvOS and visionOS. Apple said there is no indication of active exploitation for any of the vulnerabilities fixed this month.
As always, please back up your device and/or important data before attempting any updates. And please feel free to sound off in the comments if you run into any problems applying any of these fixes.
Microsoft today released updates to plug at least 121 security holes in its Windows operating systems and software, including one vulnerability that is already being exploited in the wild. Eleven of those flaws earned Microsoft’s most-dire “critical” rating, meaning malware or malcontents could exploit them with little to no interaction from Windows users.
The zero-day flaw already seeing exploitation is CVE-2025-29824, a local elevation of privilege bug in the Windows Common Log File System (CLFS) driver. Microsoft rates it as “important,” but as Chris Goettl from Ivanti points out, risk-based prioritization warrants treating it as critical.
This CLFS component of Windows is no stranger to Patch Tuesday: According to Tenable’s Satnam Narang, since 2022 Microsoft has patched 32 CLFS vulnerabilities — averaging 10 per year — with six of them exploited in the wild. The last CLFS zero-day was patched in December 2024.
Narang notes that while flaws allowing attackers to install arbitrary code are consistently top overall Patch Tuesday features, the data is reversed for zero-day exploitation.
“For the past two years, elevation of privilege flaws have led the pack and, so far in 2025, account for over half of all zero-days exploited,” Narang wrote.
Rapid7’s Adam Barnett warns that any Windows defenders responsible for an LDAP server — which means almost any organization with a non-trivial Microsoft footprint — should add patching for the critical flaw CVE-2025-26663 to their to-do list.
“With no privileges required, no need for user interaction, and code execution presumably in the context of the LDAP server itself, successful exploitation would be an attractive shortcut to any attacker,” Barnett said. “Anyone wondering if today is a re-run of December 2024 Patch Tuesday can take some small solace in the fact that the worst of the trio of LDAP critical RCEs published at the end of last year was likely easier to exploit than today’s example, since today’s CVE-2025-26663 requires that an attacker win a race condition. Despite that, Microsoft still expects that exploitation is more likely.”
Among the critical updates Microsoft patched this month are remote code execution flaws in Windows Remote Desktop services (RDP), including CVE-2025-26671, CVE-2025-27480 and CVE-2025-27482; only the latter two are rated “critical,” and Microsoft marked both of them as “Exploitation More Likely.”
Perhaps the most widespread vulnerabilities fixed this month were in web browsers. Google Chrome updated to fix 13 flaws this week, and Mozilla Firefox fixed eight bugs, with possibly more updates coming later this week for Microsoft Edge.
As it tends to do on Patch Tuesdays, Adobe has released 12 updates resolving 54 security holes across a range of products, including ColdFusion, Adobe Commerce, Experience Manager Forms, After Effects, Media Encoder, Bridge, Premiere Pro, Photoshop, Animate, AEM Screens, and FrameMaker.
Apple users may need to patch as well. On March 31, Apple released a huge security update (more than three gigabytes in size) to fix issues in a range of their products, including at least one zero-day flaw.
And in case you missed it, on March 31, 2025 Apple released a rather large batch of security updates for a wide range of their products, from macOS to the iOS operating systems on iPhones and iPads.
Earlier today, Microsoft included a note saying Windows 10 security updates weren’t available but would be released as soon as possible. It appears from browsing askwoody.com that this snafu has since been rectified. Either way, if you run into complications applying any of these updates please leave a note about it in the comments below, because the chances are good that someone else had the same problem.
As ever, please consider backing up your data and or devices prior to updating, which makes it far less complicated to undo a software update gone awry. For more granular details on today’s Patch Tuesday, check out the SANS Internet Storm Center’s roundup. Microsoft’s update guide for April 2025 is here.
For more details on Patch Tuesday, check out the write-ups from Action1 and Automox.
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.
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