Microsoft today released updates to fix at least 137 security vulnerabilities in its Windows operating systems and supported software. None of the weaknesses addressed this month are known to be actively exploited, but 14 of the flaws earned Microsoft’s most-dire “critical” rating, meaning they could be exploited to seize control over vulnerable Windows PCs with little or no help from users.

While not listed as critical, CVE-2025-49719 is a publicly disclosed information disclosure vulnerability, with all versions as far back as SQL Server 2016 receiving patches. Microsoft rates CVE-2025-49719 as less likely to be exploited, but the availability of proof-of-concept code for this flaw means its patch should probably be a priority for affected enterprises.

Mike Walters, co-founder of Action1, said CVE-2025-49719 can be exploited without authentication, and that many third-party applications depend on SQL server and the affected drivers — potentially introducing a supply-chain risk that extends beyond direct SQL Server users.

“The potential exposure of sensitive information makes this a high-priority concern for organizations handling valuable or regulated data,” Walters said. “The comprehensive nature of the affected versions, spanning multiple SQL Server releases from 2016 through 2022, indicates a fundamental issue in how SQL Server handles memory management and input validation.”

Adam Barnett at Rapid7 notes that today is the end of the road for SQL Server 2012, meaning there will be no future security patches even for critical vulnerabilities, even if you’re willing to pay Microsoft for the privilege.

Barnett also called attention to CVE-2025-47981, a vulnerability with a CVSS score of 9.8 (10 being the worst), a remote code execution bug in the way Windows servers and clients negotiate to discover mutually supported authentication mechanisms. This pre-authentication vulnerability affects any Windows client machine running Windows 10 1607 or above, and all current versions of Windows Server. Microsoft considers it more likely that attackers will exploit this flaw.

Microsoft also patched at least four critical, remote code execution flaws in Office (CVE-2025-49695, CVE-2025-49696, CVE-2025-49697, CVE-2025-49702). The first two are both rated by Microsoft as having a higher likelihood of exploitation, do not require user interaction, and can be triggered through the Preview Pane.

Two more high severity bugs include CVE-2025-49740 (CVSS 8.8) and CVE-2025-47178 (CVSS 8.0); the former is a weakness that could allow malicious files to bypass screening by Microsoft Defender SmartScreen, a built-in feature of Windows that tries to block untrusted downloads and malicious sites.

CVE-2025-47178 involves a remote code execution flaw in Microsoft Configuration Manager, an enterprise tool for managing, deploying, and securing computers, servers, and devices across a network. Ben Hopkins at Immersive said this bug requires very low privileges to exploit, and that it is possible for a user or attacker with a read-only access role to exploit it.

“Exploiting this vulnerability allows an attacker to execute arbitrary SQL queries as the privileged SMS service account in Microsoft Configuration Manager,” Hopkins said. “This access can be used to manipulate deployments, push malicious software or scripts to all managed devices, alter configurations, steal sensitive data, and potentially escalate to full operating system code execution across the enterprise, giving the attacker broad control over the entire IT environment.”

Separately, Adobe has released security updates for a broad range of software, including After Effects, Adobe Audition, Illustrator, FrameMaker, and ColdFusion.

The SANS Internet Storm Center has a breakdown of each individual patch, indexed by severity. If you’re responsible for administering a number of Windows systems, it may be worth keeping an eye on AskWoody for the lowdown on any potentially wonky updates (considering the large number of vulnerabilities and Windows components addressed this month).

If you’re a Windows home user, please consider backing up your data and/or drive before installing any patches, and drop a note in the comments if you encounter any problems with these updates.

Agents with the Federal Bureau of Investigation (FBI) briefed Capitol Hill staff recently on hardening the security of their mobile devices, after a contacts list stolen from the personal phone of the White House Chief of Staff Susie Wiles was reportedly used to fuel a series of text messages and phone calls impersonating her to U.S. lawmakers. But in a letter this week to the FBI, one of the Senate’s most tech-savvy lawmakers says the feds aren’t doing enough to recommend more appropriate security protections that are already built into most consumer mobile devices.

A screenshot of the first page from Sen. Wyden’s letter to FBI Director Kash Patel.

On May 29, The Wall Street Journal reported that federal authorities were investigating a clandestine effort to impersonate Ms. Wiles via text messages and in phone calls that may have used AI to spoof her voice. According to The Journal, Wiles told associates her cellphone contacts were hacked, giving the impersonator access to the private phone numbers of some of the country’s most influential people.

The execution of this phishing and impersonation campaign — whatever its goals may have been — suggested the attackers were financially motivated, and not particularly sophisticated.

“It became clear to some of the lawmakers that the requests were suspicious when the impersonator began asking questions about Trump that Wiles should have known the answers to—and in one case, when the impersonator asked for a cash transfer, some of the people said,” the Journal wrote. “In many cases, the impersonator’s grammar was broken and the messages were more formal than the way Wiles typically communicates, people who have received the messages said. The calls and text messages also didn’t come from Wiles’s phone number.”

Sophisticated or not, the impersonation campaign was soon punctuated by the murder of Minnesota House of Representatives Speaker Emerita Melissa Hortman and her husband, and the shooting of Minnesota State Senator John Hoffman and his wife. So when FBI agents offered in mid-June to brief U.S. Senate staff on mobile threats, more than 140 staffers took them up on that invitation (a remarkably high number considering that no food was offered at the event).

But according to Sen. Ron Wyden (D-Ore.), the advice the FBI provided to Senate staffers was largely limited to remedial tips, such as not clicking on suspicious links or attachments, not using public wifi networks, turning off bluetooth, keeping phone software up to date, and rebooting regularly.

“This is insufficient to protect Senate employees and other high-value targets against foreign spies using advanced cyber tools,” Wyden wrote in a letter sent today to FBI Director Kash Patel. “Well-funded foreign intelligence agencies do not have to rely on phishing messages and malicious attachments to infect unsuspecting victims with spyware. Cyber mercenary companies sell their government customers advanced ‘zero-click’ capabilities to deliver spyware that do not require any action by the victim.”

Wyden stressed that to help counter sophisticated attacks, the FBI should be encouraging lawmakers and their staff to enable anti-spyware defenses that are built into Apple’s iOS and Google’s Android phone software.

These include Apple’s Lockdown Mode, which is designed for users who are worried they may be subject to targeted attacks. Lockdown Mode restricts non-essential iOS features to reduce the device’s overall attack surface. Google Android devices carry a similar feature called Advanced Protection Mode.

Wyden also urged the FBI to update its training to recommend a number of other steps that people can take to make their mobile devices less trackable, including the use of ad blockers to guard against malicious advertisements, disabling ad tracking IDs in mobile devices, and opting out of commercial data brokers (the suspect charged in the Minnesota shootings reportedly used multiple people-search services to find the home addresses of his targets).

The senator’s letter notes that while the FBI has recommended all of the above precautions in various advisories issued over the years, the advice the agency is giving now to the nation’s leaders needs to be more comprehensive, actionable and urgent.

“In spite of the seriousness of the threat, the FBI has yet to provide effective defensive guidance,” Wyden said.

Nicholas Weaver is a researcher with the International Computer Science Institute, a nonprofit in Berkeley, Calif. Weaver said Lockdown Mode or Advanced Protection will mitigate many vulnerabilities, and should be the default setting for all members of Congress and their staff.

“Lawmakers are at exceptional risk and need to be exceptionally protected,” Weaver said. “Their computers should be locked down and well administered, etc. And the same applies to staffers.”

Weaver noted that Apple’s Lockdown Mode has a track record of blocking zero-day attacks on iOS applications; in September 2023, Citizen Lab documented how Lockdown Mode foiled a zero-click flaw capable of installing spyware on iOS devices without any interaction from the victim.

Earlier this month, Citizen Lab researchers documented a zero-click attack used to infect the iOS devices of two journalists with Paragon’s Graphite spyware. The vulnerability could be exploited merely by sending the target a booby-trapped media file delivered via iMessage. Apple also recently updated its advisory for the zero-click flaw (CVE-2025-43200), noting that it was mitigated as of iOS 18.3.1, which was released in February 2025.

Apple has not commented on whether CVE-2025-43200 could be exploited on devices with Lockdown Mode turned on. But HelpNetSecurity observed that at the same time Apple addressed CVE-2025-43200 back in February, the company fixed another vulnerability flagged by Citizen Lab researcher Bill Marczak: CVE-2025-24200, which Apple said was used in an extremely sophisticated physical attack against specific targeted individuals that allowed attackers to disable USB Restricted Mode on a locked device.

In other words, the flaw could apparently be exploited only if the attacker had physical access to the targeted vulnerable device. And as the old infosec industry adage goes, if an adversary has physical access to your device, it’s most likely not your device anymore.

I can’t speak to Google’s Advanced Protection Mode personally, because I don’t use Google or Android devices. But I have had Apple’s Lockdown Mode enabled on all of my Apple devices since it was first made available in September 2022. I can only think of a single occasion when one of my apps failed to work properly with Lockdown Mode turned on, and in that case I was able to add a temporary exception for that app in Lockdown Mode’s settings.

My main gripe with Lockdown Mode was captured in a March 2025 column by TechCrunch’s Lorenzo Francheschi-Bicchierai, who wrote about its penchant for periodically sending mystifying notifications that someone has been blocked from contacting you, even though nothing then prevents you from contacting that person directly. This has happened to me at least twice, and in both cases the person in question was already an approved contact, and said they had not attempted to reach out.

Although it would be nice if Apple’s Lockdown Mode sent fewer, less alarming and more informative alerts, the occasional baffling warning message is hardly enough to make me turn it off.

Microsoft today released security updates to fix at least 67 vulnerabilities in its Windows operating systems and software. Redmond warns that one of the flaws is already under active attack, and that software blueprints showing how to exploit a pervasive Windows bug patched this month are now public.

The sole zero-day flaw this month is CVE-2025-33053, a remote code execution flaw in the Windows implementation of WebDAV — an HTTP extension that lets users remotely manage files and directories on a server. While WebDAV isn’t enabled by default in Windows, its presence in legacy or specialized systems still makes it a relevant target, said Seth Hoyt, senior security engineer at Automox.

Adam Barnett, lead software engineer at Rapid7, said Microsoft’s advisory for CVE-2025-33053 does not mention that the Windows implementation of WebDAV is listed as deprecated since November 2023, which in practical terms means that the WebClient service no longer starts by default.

“The advisory also has attack complexity as low, which means that exploitation does not require preparation of the target environment in any way that is beyond the attacker’s control,” Barnett said. “Exploitation relies on the user clicking a malicious link. It’s not clear how an asset would be immediately vulnerable if the service isn’t running, but all versions of Windows receive a patch, including those released since the deprecation of WebClient, like Server 2025 and Windows 11 24H2.”

Microsoft warns that an “elevation of privilege” vulnerability in the Windows Server Message Block (SMB) client (CVE-2025-33073) is likely to be exploited, given that proof-of-concept code for this bug is now public. CVE-2025-33073 has a CVSS risk score of 8.8 (out of 10), and exploitation of the flaw leads to the attacker gaining “SYSTEM” level control over a vulnerable PC.

“What makes this especially dangerous is that no further user interaction is required after the initial connection—something attackers can often trigger without the user realizing it,” said Alex Vovk, co-founder and CEO of Action1. “Given the high privilege level and ease of exploitation, this flaw poses a significant risk to Windows environments. The scope of affected systems is extensive, as SMB is a core Windows protocol used for file and printer sharing and inter-process communication.”

Beyond these highlights, 10 of the vulnerabilities fixed this month were rated “critical” by Microsoft, including eight remote code execution flaws.

Notably absent from this month’s patch batch is a fix for a newly discovered weakness in Windows Server 2025 that allows attackers to act with the privileges of any user in Active Directory. The bug, dubbed “BadSuccessor,” was publicly disclosed by researchers at Akamai on May 21, and several public proof-of-concepts are now available. Tenable’s Satnam Narang said organizations that have at least one Windows Server 2025 domain controller should review permissions for principals and limit those permissions as much as possible.

Adobe has released updates for Acrobat Reader and six other products addressing at least 259 vulnerabilities, most of them in an update for Experience Manager. Mozilla Firefox and Google Chrome both recently released security updates that require a restart of the browser to take effect. The latest Chrome update fixes two zero-day exploits in the browser (CVE-2025-5419 and CVE-2025-4664).

For a detailed breakdown on the individual security updates released by Microsoft today, check out the Patch Tuesday roundup from the SANS Internet Storm Center. Action 1 has a breakdown of patches from Microsoft and a raft of other software vendors releasing fixes this month. As always, please back up your system and/or data before patching, and feel free to drop a note in the comments if you run into any problems applying these updates.

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 issued more than 50 security updates for its various Windows operating systems, including fixes for a whopping six zero-day vulnerabilities that are already seeing active exploitation.

Two of the zero-day flaws include CVE-2025-24991 and CVE-2025-24993, both vulnerabilities in NTFS, the default file system for Windows and Windows Server. Both require the attacker to trick a target into mounting a malicious virtual hard disk. CVE-2025-24993 would lead to the possibility of local code execution, while CVE-2025-24991 could cause NTFS to disclose portions of memory.

Microsoft credits researchers at ESET with reporting the zero-day bug labeled CVE-2025-24983, an elevation of privilege vulnerability in older versions of Windows. ESET said the exploit was deployed via the PipeMagic backdoor, capable of exfiltrating data and enabling remote access to the machine.

ESET’s Filip Jurčacko said the exploit in the wild targets only older versions of Windows OS: Windows 8.1 and Server 2012 R2. Although still used by millions, security support for these products ended more than a year ago, and mainstream support ended years ago. However, ESET notes the vulnerability itself also is present in newer Windows OS versions, including Windows 10 build 1809 and the still-supported Windows Server 2016.

Rapid7’s lead software engineer Adam Barnett said Windows 11 and Server 2019 onwards are not listed as receiving patches, so are presumably not vulnerable.

“It’s not clear why newer Windows products dodged this particular bullet,” Barnett wrote. “The Windows 32 subsystem is still presumably alive and well, since there is no apparent mention of its demise on the Windows client OS deprecated features list.”

The zero-day flaw CVE-2025-24984 is another NTFS weakness that can be exploited by inserting a malicious USB drive into a Windows computer. Barnett said Microsoft’s advisory for this bug doesn’t quite join the dots, but successful exploitation appears to mean that portions of heap memory could be improperly dumped into a log file, which could then be combed through by an attacker hungry for privileged information.

“A relatively low CVSSv3 base score of 4.6 reflects the practical difficulties of real-world exploitation, but a motivated attacker can sometimes achieve extraordinary results starting from the smallest of toeholds, and Microsoft does rate this vulnerability as important on its own proprietary severity ranking scale,” Barnett said.

Another zero-day fixed this month — CVE-2025-24985 — could allow attackers to install malicious code. As with the NTFS bugs, this one requires that the user mount a malicious virtual hard drive.

The final zero-day this month is CVE-2025-26633, a weakness in the Microsoft Management Console, a component of Windows that gives system administrators a way to configure and monitor the system. Exploiting this flaw requires the target to open a malicious file.

This month’s bundle of patch love from Redmond also addresses six other vulnerabilities Microsoft has rated “critical,” meaning that malware or malcontents could exploit them to seize control over vulnerable PCs with no help from users.

Barnett observed that this is now the sixth consecutive month where Microsoft has published zero-day vulnerabilities on Patch Tuesday without evaluating any of them as critical severity at time of publication.

The SANS Internet Storm Center has a useful list of all the Microsoft patches released today, indexed by severity. Windows enterprise administrators would do well to keep an eye on askwoody.com, which often has the scoop on any patches causing problems. Please consider backing up your data before updating, and leave a comment below if you experience any issues applying this month’s updates.