Tag Archives: WindowsKernel

July Microsoft Patch Tuesday

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July Microsoft Patch Tuesday

July Microsoft Patch Tuesday. In the second week of July, I was on vacation in St. Petersburg. After that, I got caught up with a bunch of other tasks, so I'm only publishing this roundup now. Better late than never, especially considering how unusual this MSPT turned out to be. 😉 In total, 571 vulnerabilities were addressed - almost three times (❗️) more than in June. There are four vulnerabilities that have been reported as exploited in the wild:

🔻 RCE - Microsoft SharePoint (CVE-2026-58644). An attacker with Site Owner privileges or higher can remotely inject and execute arbitrary code on the SharePoint Server.

🔻 RCE - Microsoft SharePoint (CVE-2026-50522). The vulnerability description is identical to CVE-2026-58644. According to ZDI, the CVE-2026-50522 vulnerability was successfully demonstrated at Pwn2Own Berlin. Despite this, Microsoft rates its Exploit Maturity as "Unknown", even though researchers have already provided a working exploit to the company. This once again shows that organizations should not rely solely on software vendors' assessments and should instead perform their own risk evaluation. If you have Internet-facing SharePoint servers, you should test and deploy the patch addressing this vulnerability as soon as possible.

🔻 EoP - Microsoft SharePoint Server (CVE-2026-56164). Missing authentication for a critical function in Microsoft Office SharePoint could allow an unauthenticated attacker to elevate privileges over a network. Microsoft mentioned in the advisory that enabling the Antimalware Scan Interface (AMSI) on the server and setting the Request Body Scan mode to Full can help mitigate this flaw.

🔻 EoP - Active Directory Federation Services (CVE-2026-56155). Insufficient granularity of access control (CWE-1220) in Active Directory Federation Services (AD FS) allows an authorized attacker to elevate privileges locally. An attacker who successfully exploited this vulnerability could gain administrator privileges.

There are eight more vulnerabilities with publicly available exploits:

🔸 EoP - Windows User Interface Core (CVE-2026-50454). Relative path traversal (CWE-23) allows an authorized attacker to elevate privileges locally. An attacker who successfully exploited this vulnerability could gain SYSTEM privileges. The PoC starts from a normal, non-elevated process belonging to a local administrator and opens an interactive command prompt as NT AUTHORITY\SYSTEM.

🔸 EoP - Windows WalletService (CVE-2026-49176). Improper privilege management (CWE-269) allows an authorized attacker to elevate privileges locally. The exploit PoC starts a command prompt as SYSTEM in the active desktop session.

🔸 RCE - Microsoft Message Queuing Queue Manager (CVE-2026-54992). The existing exploit PoC demonstrates denial of service; it does not demonstrate code execution.

🔸 EoP - Windows Narrator Braille (CVE-2026-58635). According to Microsoft's description, an attacker who successfully exploited this vulnerability could execute code in the security context of the NT AUTHORITY\Network Service account. However, the description of the exploit PoC states that an unprivileged attacker would gain NT AUTHORITY\SYSTEM privileges.

🔸 EoP - Windows Cloud Files Mini Filter Driver (CVE-2026-58613). Use after free (CWE-416) in the Windows Cloud Files Mini Filter Driver allows an authorized attacker to elevate privileges locally. An attacker who successfully exploits this vulnerability can gain SYSTEM privileges. Exploitation details are available in the Talos Vulnerability Report TALOS-2026-2426.

🔸 InfDisc - Windows Win32k (CVE-2026-50416). An attacker who successfully exploited this vulnerability could potentially read small portions of heap memory. The exploit PoC description mentions Chrome tabs, Discord, Explorer, Spotify, and tray windows. However, it seems that it will not be possible to intercept passwords using this vulnerability.

🔸 InfDisc - Windows Kernel (CVE-2026-50475). A buffer over-read (CWE-126) in the Windows Kernel allows an authorized attacker to disclose information locally. Exploitation details are available in the Talos Vulnerability Report TALOS-2026-2443.

🔸 EoP - Azure Spring Apps (CVE-2026-50338). An attacker who successfully exploited this vulnerability could gain elevated privileges, potentially allowing them to perform actions beyond their original permissions. According to the author of the exploit PoC, the vulnerability is a Spring Cloud Azure B2C resource server cross-issuer authentication bypass.

Among the remaining vulnerabilities, the following can be highlighted:

🔹 RCE - Windows Remote Desktop Protocol (CVE-2026-56190). An unauthenticated, network-reachable, no user interaction required vulnerability. The root cause is a classic one: the use of an uninitialized resource (CWE-908), meaning specially crafted RDP traffic can interact with memory that was never properly initialized, letting an attacker corrupt memory and potentially steer code execution. RDP Servers are a common target, so audit your systems to see which are internet accessible and start from there.

🔹 RCE - Microsoft Dynamics NAV and Microsoft Dynamics 365 Business Central (On Premises) (CVE-2026-55944). Successful exploitation can be achieved by sending a crafted login request to an affected Dynamics NAV or Business Central server in order to trigger a deserialization of untrusted data vulnerability. Microsoft's advisory cautions that no user-interaction is required, nor is authentication a requirement in order to successfully exploit this vulnerability.

🔹 EoP - Microsoft Windows VMSwitch (CVE-2026-57092). It's a use-after-free that lets a low-privileged attacker escalate to full host compromise across a VM boundary. ZDI reported that a similar exploit was demonstrated on ESXi at Pwn2Own Berlin, but this issue is not limited to ESXi. If you use VMSwitch in Hyper-V deployments (which is likely), test and deploy the fix quickly.

🔹 Spoofing - Microsoft Exchange (CVE-2026-55008). An attacker can send a specially crafted email that runs arbitrary JavaScript when the victim opens it in OWA. No attachment or macro is required - simply viewing the email is enough. If your organization uses OWA, it is recommended to test and deploy the fix as soon as possible.

🔹 RCE - Windows DHCP Server (CVE-2026-50518, CVE-2026-56159, CVE-2026-48564, CVE-2026-50370), Windows DHCP Client (CVE-2026-54128), Windows Message Queuing Service (MSMQ) (CVE-2026-50447), Windows Admin Center (WAC) (CVE-2026-56196), Windows FTP Service (CVE-2026-49172), Windows GDI+ (CVE-2026-50380), Windows Server Network driver (CVE-2026-56188), Microsoft Exchange (CVE-2026-55005), Windows Active Directory Domain Services (CVE-2026-49178), Windows Remote Desktop Client (CVE-2026-50474), Windows Remote Desktop Client (CVE-2026-54990, CVE-2026-58594), Windows TCP/IP (CVE-2026-54999), Windows Print Spooler (CVE-2026-58608), Windows Reliable Multicast Transport Driver (RMCAST) (CVE-2026-54982, CVE-2026-54995), Microsoft SQL Server (CVE-2026-54117), Microsoft Copilot (CVE-2026-48561).

🔹 SFB - Microsoft SharePoint Server (CVE-2026-55040).

🔹 EoP - Windows Server Update Service (WSUS) (CVE-2026-50444), Active Directory Certificate Services (CVE-2026-54121).

There is also a rather curious vulnerability:

RCE - Game: Age of Empires II: Definitive Edition (CVE-2026-50663). 😃 A relative path traversal in Age of Empires II: Definitive Edition Game allows an unauthorized attacker to execute code over a network. Age of Empires II is a cult classic real-time strategy game by Microsoft, set in the medieval era. Players develop chosen civilizations, manage resources, research technologies, and command armies in historical campaigns and multiplayer battles. The Definitive Edition features improved graphics, updated audio, and additional content. If you're still playing this game, be sure to update. 😉

🗒 Full Vulristics Report

June Microsoft Patch Tuesday

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June Microsoft Patch Tuesday

June Microsoft Patch Tuesday. Last week I was on vacation in Veliky Novgorod, so I'm publishing this overview only now. A total of 202 vulnerabilities were addressed, approximately twice as many as in May. There are currently no vulnerabilities marked as exploited in the wild. However, there are two vulnerabilities with publicly available exploits:

🔸 RCE - HTTP.sys (CVE-2026-47291). This critical vulnerability allows remote, unauthenticated attackers to execute arbitrary code on affected systems without user interaction. However, systems using the default MaxRequestBytes registry value in the Windows HTTP stack are not affected. If needed, you can change this registry setting to protect systems while testing and deploying the patch. Microsoft's security bulletin includes instructions and a PowerShell script for this workaround.

🔸 DoS - HTTP.sys (CVE-2026-49160). The same exploit is used as for the previous RCE vulnerability.

It is also worth paying attention to vulnerabilities that Microsoft has flagged as having a publicly available exploit:

🔹 SFB - Windows BitLocker (CVE-2026-50507). A successful attacker could bypass the BitLocker Device Encryption feature on the system storage device. An attacker with physical access to the target could exploit this vulnerability to gain access to encrypted data. According to Tenable, this is the "Bitskrieg" vulnerability discovered by the researcher known as Chaotic Eclipse/Nightmare Eclipse.

🔹 SFB - Secure Boot (CVE-2026-48570). An attacker who successfully exploited this vulnerability could bypass Secure Boot. This vulnerability was reported by Alon Leviev (STORM), who is known for previous research related to BootKitty and BlackLotus.

Among the remaining vulnerabilities, the following are worth highlighting:

🔹 RCE - Windows Kernel (CVE-2026-45657). This vulnerability allows remote, unauthenticated attackers to run code with SYSTEM privileges without any user interaction. In other words, it could be used to spread automatically between systems. The issue is caused by how the Windows kernel processes TCP/IP traffic. Microsoft rated this as "Exploitation Less Likely", but security researchers and exploit developers are already analyzing the patch and trying to build an exploit. Test and deploy this patch as soon as possible.

🔹 EoP - Windows Collaborative Translation Framework (CTFMON) (CVE-2026-45586). This vulnerability affects a component used for voice and handwriting recognition. If exploited, an attacker could gain SYSTEM privileges. Microsoft rates this vulnerability as "Exploitation More Likely".

🔹 RCE - Windows Remote Desktop Client (CVE-2026-42909, CVE-2026-42913, CVE-2026-42985, CVE-2026-42992, CVE-2026-42993, CVE-2026-44799, CVE-2026-44801, CVE-2026-47289, CVE-2026-47653, CVE-2026-47654, CVE-2026-48563). Successful exploitation would require a victim to connect to an attacker-controlled server using an affected version of the Remote Desktop Client. This action could trigger a heap-based buffer overflow, resulting in remote code execution.

🔹 RCE - DHCP Client Service (CVE-2026-44815). This vulnerability allows remote, unauthenticated attackers to execute code on affected systems without user interaction. Because the DHCP client is widely enabled across Windows systems, this vulnerability presents a broad attack surface. Organizations should prioritize testing and deploying the patch for this vulnerability as soon as possible.

🗒 Full Vulristics report

May Microsoft Patch Tuesday

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May Microsoft Patch Tuesday

May Microsoft Patch Tuesday. A total of 119 vulnerabilities, approximately 1.5 times fewer than in April. There are currently no vulnerabilities marked as actively exploited in the wild. However, there is one vulnerability with a public exploit:

🔸 EoP - Windows Kernel (CVE-2026-40369). A detailed write-up and exploit for this vulnerability were published on May 14, two days after the May MSPT. The researcher describes exploitation of the vulnerability as follows: "A single syscall from any unprivileged process — including inside Chrome's renderer sandbox — can increment arbitrary kernel memory addresses. No race conditions. No heap spray. No special tokens. 100% deterministic privilege escalation to SYSTEM."

Among the remaining ones, the following stand out:

🔹 RCE - Windows DNS Client (CVE-2026-41096). A ZDI analyst commented on this vulnerability as follows: "This patch fixes a heap-based buffer overflow in the DNS Client triggered by a malicious DNS response. No authentication or user interaction needed, and since the DNS Client runs on virtually every Windows machine, the attack surface is enormous. An attacker with a position to influence DNS responses (MitM, rogue server) could achieve unauthenticated RCE across your enterprise."

🔹 RCE - Windows Netlogon (CVE-2026-41089). The vulnerability allows an unauthenticated remote attacker to execute arbitrary code on a domain controller by sending a specially crafted network request. Exploitation does not require credentials or user interaction, which classifies this vulnerability as wormable. Compromise of a domain controller means full compromise of the organization's entire domain. A Rapid7 analyst added in their commentary: "No privileges or user interaction are required, and attack complexity is low, which suggests that creation of a reliable exploit might not be especially difficult for anyone with knowledge of the specific mechanism. Microsoft assesses exploitation as less likely, but since those exploitability assessments are provided without an accompanying explanation, it's not clear how much reassurance defenders should take. Anyone who remembers the much-discussed CVE-2020-1472 (aka ZeroLogon) back in 2020 will note that CVE-2026-41089 offers an attacker more immediate control of a domain controller. Patches are available for all versions of Windows Server from 2012 onwards."

🔹 RCE - Windows TCP/IP (CVE-2026-40415). Commentary from a ZDI analyst: "This bug in the TCP/IP stack results from a use-after-free (UAF) and could allow a remote, unauthenticated threat actor to execute code without user interaction. That makes this another wormable bug. However, this one is much less likely to be exploited. The target needs to be under sustained low-memory (memory pressure) conditions, which is pretty rare."

🔹 RCE - Microsoft Word (CVE-2026-40361, CVE-2026-40364, CVE-2026-40366, CVE-2026-40367). An attacker can exploit these vulnerabilities through social engineering by sending a malicious file to a targeted victim. Successful exploitation would grant the attacker arbitrary code execution. Microsoft researchers note that the Preview Pane is an attack vector for each of these vulnerabilities.

🔹 RCE - Microsoft Office (CVE-2026-40363, CVE-2026-42831). A heap-based buffer overflow vulnerability in Microsoft Office may allow an unauthorized attacker to remotely execute arbitrary code.

🔹 RCE - Windows GDI (CVE-2026-35421). A heap-based buffer overflow vulnerability in the Windows GDI component may allow an unauthorized attacker to remotely execute arbitrary code.

🔹 RCE - Microsoft Dynamics 365 On-Premises (CVE-2026-42898). Commentary from a ZDI analyst: "It allows any authenticated user to execute code with a scope change, meaning exploitation can break out and affect resources beyond the vulnerable component itself. Scope changes are pretty rare, so if you're running Dynamics 365 On-Prem, definitely test and deploy this patch quickly."

🔹 EoP - Windows Kernel (CVE-2026-33841, CVE-2026-35420, CVE-2026-40369). CVE-2026-33841 and CVE-2026-40369 are rated "Exploitation More Likely". A local attacker can use these vulnerabilities to elevate privileges to SYSTEM level. In the case of CVE-2026-33841, the attacker can elevate privileges to Medium/High integrity level.

🗒 Full Vulristics report

Trending vulnerabilities for June according to Positive Technologies

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Trending vulnerabilities for June according to Positive Technologies. Traditionally, in 3 formats (in Russian):

📹 The section "Trending VM" in the SecLab news video (starts at 15:03)
🗞 Post on the Habr website, in fact this is a slightly expanded scenario for the "Trending VM" section
🗒 Compact digest with technical details on the official PT website

List of vulnerabilities:

🔻 EoP in Microsoft Windows CSC (CVE-2024-26229)
🔻 EoP in Microsoft Windows Error Reporting (CVE-2024-26169)
🔻 EoP in Microsoft Windows Kernel (CVE-2024-30088)
🔻 RCE in PHP (CVE-2024-4577)
🔻 EoP in Linux Kernel (CVE-2024-1086)
🔻 InfDisclosure in Check Point Security Gateways (CVE-2024-24919)
🔻 RCE in VMware vCenter (CVE-2024-37079, CVE-2024-37080)
🔻 AuthBypass in Veeam Backup & Replication (CVE-2024-29849)

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The severity of the Elevation of Privilege - Windows Kernel (CVE-2024-30088) has increased

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The severity of the Elevation of Privilege - Windows Kernel (CVE-2024-30088) has increased

The severity of the Elevation of Privilege - Windows Kernel (CVE-2024-30088) has increased. The vulnerability is fresh, it is from the June Microsoft Patch Tuesday. I highlighted it in the review because, according to the CVSS vector, there was a private Proof-of-Concept Exploit for it. But there were no details. It was only clear that in case of successful exploitation, the attacker gains SYSTEM privileges. According to the ZDI advisory, the vulnerability affects the implementation of NtQueryInformationToken and is due to the lack of proper locking when performing operations on the object.

On June 24, 2 weeks after the June Patch Tuesday, a repository with technical details on this vulnerability and PoC appeared on GitHub. A video of running the utility to obtain SYSTEM privileges is also available.

A lot of exploits have begun to appear for Windows EoP/LPE vulnerabilities recently. Fix them in advance!

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June Microsoft Patch Tuesday

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June Microsoft Patch Tuesday

June Microsoft Patch Tuesday. There are 69 vulnerabilities in total, 18 of which were added between May and June Patch Tuesday. Among these added were 2 vulnerabilities with signs of exploitation in the wild:

🔻 Remote Code Execution - Chromium (CVE-2024-5274, CVE-2024-4947). Both vulnerabilities are in CISA KEV; there are no exploits for them yet.

For the remaining vulnerabilities, there are no formal signs of exploitation in the wild or public exploits yet.

The specialized InfoSec media pay attention to these 2:

🔸 Remote Code Execution - Microsoft Message Queuing (MSMQ) (CVE-2024-30080). This vulnerability has a high CVSS Score of 9.8. To get RCE, the attacker sends a specially crafted malicious packet to the MSMQ server. The vulnerability may well become wormable for Windows servers with MSMQ enabled. It is very similar to last year's QueueJumper (CVE-2023-21554).
🔸 Denial of Service - DNSSEC (CVE-2023-50868). Vulnerability in DNSSEC validation. An attacker can cause DoS using standard DNS integrity protocols. 🤷‍♂️ I don’t see any super criticality, but this is rare for MS Patch Tuesday, which is probably why everyone is writing about it.

What else you can pay attention to:

🔸 Elevation of Privilege - Windows Win32k (CVE-2024-30091), Windows Kernel (CVE-2024-30088, CVE-2024-30099) and Windows Cloud Files Mini Filter Driver (CVE-2024-30085). Why these? Microsoft's CVSS states that there are private Proof-of-Concept exploits for them.
🔸 Remote Code Execution - Microsoft Office (CVE-2024-30101). This is a Microsoft Outlook vulnerability. To successfully exploit this vulnerability, a user must open a malicious email in an affected version of Microsoft Outlook and then perform certain actions to trigger the vulnerability. It's enough to open the email in the Preview Pane. However, to successfully exploit this vulnerability, an attacker needs to win the race condition.
🔸 Remote Code Execution - Microsoft Outlook (CVE-2024-30103). Preview Pane is a vector. Authentication required. The vulnerability is somehow related to the creation of malicious DLL files. 🤷‍♂️
🔸 Remote Code Execution - Windows Wi-Fi Driver (CVE-2024-30078). An attacker can execute code on a vulnerable system by sending a specially crafted network packet. The victim must be within the attacker's Wi-Fi range and use a Wi-Fi adapter. Sounds interesting, let's wait for details. 😈
🔸 Remote Code Execution - Microsoft Office (CVE-2024-30104). An attacker must send the user a malicious file and convince the user to open the file. The Preview Pane is NOT an attack vector.

🗒 Vulristics report on June Microsoft Patch Tuesday

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First impressions of the March Microsoft Patch Tuesday

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First impressions of the March Microsoft Patch Tuesday
First impressions of the March Microsoft Patch TuesdayFirst impressions of the March Microsoft Patch TuesdayFirst impressions of the March Microsoft Patch TuesdayFirst impressions of the March Microsoft Patch TuesdayFirst impressions of the March Microsoft Patch TuesdayFirst impressions of the March Microsoft Patch TuesdayFirst impressions of the March Microsoft Patch Tuesday

First impressions of the March Microsoft Patch Tuesday. So far I have not seen anything overtly critical. There are 80 vulnerabilities in total, including 20 added between the February and March MSPT.

With PoC there is only one:

🔻 Information Disclosure - runc (CVE-2024-21626). It allows an attacker to escape from the container. What does Microsoft have to do with it? The vulnerability has been fixed in Azure Kubernetes Service and CBL-Mariner (Microsoft's internal Linux distribution).

For the rest, there are no signs of active exploitation or the existence of a PoC yet.

We can pay attention to the following:

🔸 Elevation of Privilege - Windows Kernel (CVE-2024-21443, CVE-2024-26173, CVE-2024-26176, CVE-2024-26178, CVE-2024-26182). Such vulnerabilities often become exploitable recently. The same applies to Elevation of Privilege - Windows Print Spooler (CVE-2024-21433).
🔸 Remote Code Execution - Open Management Infrastructure (OMI) (CVE-2024-21334). CVSS 9.8 and ZDI write that "it would allow a remote, unauthenticated attacker to execute code on OMI instances on the Internet". Perhaps such instances are indeed often accessible via the Internet, this requires research. 🤷‍♂️
🔸 Remote Code Execution - Windows Hyper-V (CVE-2024-21407). This "guest-to-host escape" vulnerability was highlighted by everyone: Qualys, Tenable, Rapid7, ZDI.
🔸 Remote Code Execution - Microsoft Exchange (CVE-2024-26198). This is a "DLL loading" vulnerability. The details are still unclear, but I wouldn’t be surprised if there will be a detailed write-up on it soon.

🗒 Vulristics report

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