Tag Archives: Win32k

July Microsoft Patch Tuesday

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

December Microsoft Patch Tuesday

December Microsoft Patch Tuesday

December Microsoft Patch Tuesday. A total of 56 vulnerabilities were fixed - 9 fewer than in November. There is one vulnerability with confirmed in-the-wild exploitation:

🔻 EoP - Windows Cloud Files Mini Filter Driver (CVE-2025-62221)

There are currently no vulnerabilities with publicly available exploits. Among the remaining vulnerabilities, the following stand out:

🔹 RCE - Microsoft Office (CVE-2025-62554, CVE-2025-62557), Microsoft PowerShell (CVE-2025-54100), Microsoft Outlook (CVE-2025-62562), GitHub Copilot for JetBrains (CVE-2025-64671)
🔹 EoP - Windows Win32k (CVE-2025-62458), Windows Cloud Files Mini Filter Driver (CVE-2025-62454, CVE-2025-62457), Windows Common Log File System Driver (CVE-2025-62470), Windows Remote Access Connection Manager (CVE-2025-62472), Windows Storage (CVE-2025-59516)

🗒 Full Vulristics report

На русском

June Microsoft Patch Tuesday

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

На русском

October 2023: back to Positive Technologies, Vulristics updates, Linux Patch Wednesday, Microsoft Patch Tuesday, PhysTech VM lecture

October 2023: back to Positive Technologies, Vulristics updates, Linux Patch Wednesday, Microsoft Patch Tuesday, PhysTech VM lecture. Hello everyone! October was an interesting and busy month for me. I started a new job, worked on my open source Vulristics project, and analyzed vulnerabilities using it. Especially Linux vulnerabilities as part of my new Linux Patch Wednesday project. And, of course, analyzed Microsoft Patch Tuesday as well. In addition, at the end of October I was a guest lecturer at MIPT/PhysTech university. But first thing first.

Alternative video link (for Russia): https://vk.com/video-149273431_456239138

Continue reading

Microsoft Patch Tuesday May 2023: Microsoft Edge, BlackLotus Secure Boot SFB, OLE RCE, Win32k EoP, NFS RCE, PGM RCE, LDAP RCE, SharePoint RCE

Microsoft Patch Tuesday May 2023: Microsoft Edge, BlackLotus Secure Boot SFB, OLE RCE, Win32k EoP, NFS RCE, PGM RCE, LDAP RCE, SharePoint RCE. Hello everyone! This episode will be about Microsoft Patch Tuesday for May 2023, including vulnerabilities that were added between April and May Patch Tuesdays.

Alternative video link (for Russia): https://vk.com/video-149273431_456239126

As usual, I use my open source Vulristics project to analyse and prioritize vulnerabilities. I took the comments about the vulnerabilities from the Qualys, Tenable, Rapid7, ZDI Patch Tuesday reviews.

It’s been a long time since we’ve had such tiny Patch Tuesday. 57 CVEs, including CVEs appeared during the month. And only 38 without them! 😄

Continue reading

Microsoft Patch Tuesday January 2022

Microsoft Patch Tuesday January 2022. Hello everyone! This episode will be about Microsoft Patch Tuesday for January 2022. Traditionally, I will use my open source Vulristics tool for analysis. This time I didn’t make any changes to how connectors work. The report generation worked correctly on the first try.

python3.8 vulristics.py --report-type "ms_patch_tuesday" --mspt-year 2022 --mspt-month "January" --rewrite-flag "True"

The only thing I have improved is the detection of types of vulnerabilities and vulnerable products. “Unknown Vulnerability Type” was for two vulnerabilities, so I added the “Elevation Of Privilege” и “Cross-Site Scripting” spelling options. I added detections for 13 products and 19 Windows components. I also corrected the method for sorting vulnerabilities with the same Vulristics score. Previously, such vulnerabilities were sorted by CVE id, now they are sorted by vulnerability type and product. This allows you to see the clusters of similar vulnerabilities.

Continue reading

Vulristics: Microsoft Patch Tuesdays Q2 2021

Vulristics: Microsoft Patch Tuesdays Q2 2021. Hello everyone! Let’s now talk about Microsoft Patch Tuesday vulnerabilities for the second quarter of 2021. April, May and June. Not the most exciting topic, I agree. I am surprised that someone is reading or watching this. For me personally, this is a kind of tradition. Plus this is an opportunity to try Vulristics in action and find possible problems. It is also interesting to see what VM vendors considered critical back then and what actually became critical. I will try to keep this video short.

First of all, let’s take a look at the vulnerabilities from the April Patch Tuesday. 108 vulnerabilities, 55 of them are RCEs. Half of these RCEs (27) are weird RPC vulnerabilities. “Researcher who reported these bugs certainly found quite the attack surface”. The most critical vulnerability is RCE in Exchange (CVE-2021-28480). This is not ProxyLogon, this is another vulnerability. ProxyLogon was in March. And this vulnerability is simply related to ProxyLogon, so it is believed that it is exploited in the wild as well. In the second place this Win32k Elevation of Privilege (CVE-2021-28310). It is clearly mentioned in several sources as being used in real attacks. “Bugs of this nature are typically combined with other bugs, such as a browser bug or PDF exploit, to take over a system”. And the only vulnerability with a public exploit is the Azure DevOps Server Spoofing (CVE-2021-28459). Previously known as Team Foundation Server (​TFS), Azure DevOps Server is a set of collaborative software development tools. It is hosted on-premises. Therefore, this vulnerability can be useful for attackers.

Continue reading