Improper access control in Windows MultiPoint Services (CVE-2025-54116) allows a locally authorized attacker to elevate their privileges on an affected host. (msrc.microsoft.com)
Executive summary
- What it is: CVE-2025-54116 is an elevation-of-privilege (EoP) vulnerability in Microsoft’s Windows MultiPoint Services component. The vulnerability arises from improper access control in MultiPoint Services and can allow an attacker who already has some level of local access to the machine to gain higher privileges. (msrc.microsoft.com)
- Attack vector / prerequisites: Local (the attacker must already have an account or code-execution capability on the host). Exploitation requires the ability to run code or otherwise make calls under the attacker’s local (non‑privileged) identity.
- Impact: Local privilege escalation — an attacker could escalate from a limited user to a higher-privilege account (up to SYSTEM), permitting system-configuration changes, installation of persistent tooling (backdoors/ransomware), credential theft, or disabling security controls.
- What to do immediately: Apply the Microsoft security update(s) that remediate CVE-2025-54116; if you cannot patch immediately, mitigate by reducing local attack surface, removing/uninstalling MultiPoint Services where not required, hardening local accounts, enabling EDR/telemetry, and applying least-privilege controls. For general patching and mitigation guidance for Microsoft vulnerabilities see Microsoft’s guidance and standard remediation playbooks. (msrc.microsoft.com)
- Component: Windows MultiPoint Services is a Windows component historically used in classroom/multi-user scenarios to let multiple users share a single machine. The MSRC short advisory description for CVE-2025-54116 states the underlying weakness as “improper access control” that allows an authorized (local) attacker to elevate privileges on the host. Because the flaw is an access control / authorization bug, the attacker must already be able to operate locally under some account and then abuse the improper checks to get higher privileges. (msrc.microsoft.com)
- Why this class of flaw matters: Authorization / access-control bugs are often high-value for attackers because they don’t require complex memory-corruption exploitation; once an attacker has a foothold (for example via phishing, a malicious document, a compromised service account, or a container escape), an EoP lets them move from that foothold into system-level control. Recent vendor advisories and community guidance emphasize immediate patch rollout and improving local hardening when these EoP issues are disclosed.
- Any system that has the vulnerable Windows MultiPoint Services component installed and is running the versions Microsoft lists as affected on the MSRC page for CVE-2025-54116 is potentially at risk. Because MultiPoint Services is not present on every Windows installation, the first step for defenders is to identify hosts that have the component installed and prioritize them for patching.
- For authoritative affected-platform, KB, and update mapping, use Microsoft’s Security Update Guide entry for CVE-2025-54116 (the MSRC entry is the canonical source). (msrc.microsoft.com)
- Exploit complexity: This is a local EoP; complexity depends on how MultiPoint Services exposes the vulnerable functionality. Many access-control issues can be exploited with relatively low complexity once an attacker has local interaction.
- Precondition: local presence on a target host (non‑privileged account or ability to run code under a non‑privileged account) is required, so CVE-2025-54116 is not a remote, unauthenticated worm‑type issue. However, in environments that run untrusted code (public kiosks, classroom/shared desktops, developer build machines, VDI/RDS/terminal servers) or in multi‑tenant situations, the risk is materially higher because attacker footholds are more likely.
- Chaining potential: Because EoP is usually the step between an initial foothold and full system compromise, this vulnerability can be chained with other issues (malicious documents, LPEs in other components, weak local credentials) to produce full host takeover. This is why immediate patching and reducing local code-execution exposures are important.
- Microsoft’s Security Update Guide entry for CVE-2025-54116 gives the high-level description (improper access control in Windows MultiPoint Services; local elevation of privilege). The MSRC entry is the authoritative place to:
- Confirm the exact affected SKUs and builds,
- Get the CVSS rating and Microsoft’s exploitation assessment,
- Obtain the KB/article numbers that map to the cumulative updates or out-of-band fixes you must install. (msrc.microsoft.com)
- Inventory — find hosts with MultiPoint Services
- Identify machines that have the MultiPoint Services role or components installed. Use your asset management / software inventory or run a targeted audit across endpoints/servers (see “How to detect” below).
- Patch — apply vendor updates
- Install the Microsoft security update(s) that fix CVE-2025-54116 as listed in the MSRC Security Update Guide. Use Windows Update, WSUS, SCCM/ConfigMgr, Microsoft Intune/Windows Update for Business, or the Microsoft Update Catalog for offline patching. Verify the KB numbers on MSRC for the exact packages to deploy. (msrc.microsoft.com)
- If you cannot patch immediately — mitigate
- Uninstall or disable MultiPoint Services where it is not required (remove the role/feature in Server Manager / Programs & Features, or disable the associated services).
- Limit local accounts and remove local administrator rights from users who don’t need them; enforce least privilege and use separate admin accounts.
- Enable application control (WDAC or AppLocker) to prevent the execution of untrusted binaries and restrict where unsigned code can run.
- Ensure EDR/antivirus is active and collecting telemetry (enable high-fidelity blocking/detection rules).
- Segment and isolate high-value hosts (jump boxes, admin workstations) from user networks until patched.
- Map CVE → KB: go to the MSRC/Update Guide page for CVE-2025-54116 and note the KB article(s) Microsoft lists for each affected product/build. (msrc.microsoft.com)
- Use your patch-management system to approve and deploy those updates to the affected rings (test ring → pilot → broad deployment).
- Manual checks (single host):
- Windows Update (UI): Settings → Update & Security → Windows Update → Check for updates.
- PowerShell (install and verify):
- To check installed updates: Get-HotFix | Where-Object {$_.HotFixID -like "KB*"}
- To query update history via Windows Update Agent: (Get-WUHistory) — if using PSWindowsUpdate module.
- Microsoft Update Catalog: download the offline KB package if you need to stage an image or disconnect a host before installing.
- After installing, confirm the host’s installed KB list includes the update(s) listed on the MSRC advisory.
- The vulnerability is local-EoP, so detection is best focused on:
- Unusual local process creations that escalate privileges (e.g., a low‑privilege process launching cmd.exe/powershell.exe with SYSTEM-like behavior).
- Security event log markers: look for privileged logons and token creation events (Event IDs such as 4672 — “Special privileges assigned to new logon”, 4688 — “Process creation”, 4624 variants for logon types), and sudden changes to service startup or new scheduled tasks.
- EDR alerts for process injection, suspicious use of token manipulation APIs, or attempts to write system files.
- Sample (generic) Kusto/Advanced Hunting queries for Defender/EDR (adapt to your tooling):
- Find process creations by non-admin users that spawn cmd/powershell:
DeviceProcessEvents
| where InitiatingProcessAccountName != "SYSTEM" and (FileName has "powershell.exe" or FileName has "cmd.exe")
| where ProcessCommandLine has_any ("-EncodedCommand","-nop","-w hidden") - Find assignment of special privileges (requires mapping to event logs and EDR): map Windows Security events 4672 and correlate with recent process creation on that host.
- Find process creations by non-admin users that spawn cmd/powershell:
- Tune alerts for post-exploit activity (credential dumping, persistence). EDR telemetry often detects the actions attackers perform after an EoP even if the initial authorization abuse is not visible.
- Uninstall or disable the MultiPoint Services component where it is unnecessary. Role/feature removal is the most direct risk elimination for this class of bug.
- Principle of least privilege: remove unnecessary local admin rights or use Just-In-Time and Just-Enough-Administration patterns for privileged access.
- Application allowlisting (WDAC/AppLocker): prevents unauthorized or unknown binaries from running even if a process attempts to escalate privileges.
- Enable and harden Endpoint Detection and Response (EDR) to log kernel and process telemetry; ensure centralized collection and retention so you can hunt and do post‑compromise forensics.
- Kernel hardening options: consider enabling features like Memory Integrity (HVCI) and Control Flow Guard where compatible, to reduce the success rate of local exploit chains that rely on kernel or driver exploitation.
- Isolate the machine from the network to reduce lateral movement.
- Preserve volatile data: collect a full memory image and EDR artifacts. Export Windows event logs, Sysmon logs (if present), and device EDR telemetry.
- Look for indicators of privilege escalation: new services, scheduled tasks, changes to service DLLs, DLL side-loading, new local admin accounts, or tools commonly used for post‑exploitation (Mimikatz, credential dumper tools).
- If confirmed compromise is suspected and you cannot assert full remediation, reimage the host. Capture forensic evidence before reimaging.
- Access-control bugs in privileged or service components are attractive for attackers because they usually require only an initial foothold and can lead to SYSTEM-level control.
- Similar patterns have been observed across multiple Microsoft components in recent months where privileged-upgrade flows or “link following” and authorization bypass issues were fixed; defenders should treat this CVE with similar urgency as other local elevation advisories and follow standard hardening playbooks.
- Visit the MSRC Security Update Guide page for CVE-2025-54116 and capture the KB/update mapping. (msrc.microsoft.com)
- Inventory: find hosts with MultiPoint Services installed.
- Test: apply the update(s) in a test ring (image/VM/test systems).
- Deploy: roll updates to production according to risk profile — prioritize hosts where code-execution by non-admins is possible or hosts that are internet‑facing / multi-user.
- Mitigate: where patching must be delayed, uninstall/disable MultiPoint Services, restrict local admin access, enable WDAC/AppLocker, and ensure EDR is monitoring.
- Monitor: hunt for suspicious process creations, privilege-assignment events, and persistence indicators.
- Document: record which hosts were updated, which were mitigated by uninstall/disabling, and keep a remediation log for compliance and auditing.
Q: Does CVE-2025-54116 allow remote, unauthenticated attackers to take over systems?
A: No — the MSRC description indicates this is a local elevation of privilege via improper access control. An attacker must already have a local account or the ability to run code locally on the target for this CVE to be usable. (msrc.microsoft.com)
Q: Is there a public exploit or active attacks reported?
A: You should consult the MSRC page for the exploitation assessment. At disclosure vendors will often state whether they observed active exploitation; if MSRC’s advisory does not list active exploitation, assume it is not publicly acknowledged — but act to patch promptly because EoP vulnerabilities are often quickly weaponized once details are known. (msrc.microsoft.com)
Q: Can I remove MultiPoint Services instead of patching?
A: Yes — removing or disabling the affected component is a valid and often recommended mitigation if your organization does not rely on MultiPoint functionality. Uninstall the role/feature in Server Manager or the equivalent control panel interface, then re-audit to ensure the feature and services are gone. If the component is required, apply the vendor patch as soon as possible.
Q: Which logs/events are most useful for detection?
A: Windows Security logs (events such as 4672, 4688, 4634/4624), Sysmon if enabled (process creation, network connections), and EDR telemetry. Look for unusual token use, process creation from unprivileged contexts, and changes to service configurations. Use centralized SIEM queries to correlate across machines.
References and further reading
- Microsoft Security Update Guide — CVE-2025-54116 (authoritative advisory entry). Use this page to get KB numbers and per‑SKU remediation guidance. (msrc.microsoft.com)
- General Microsoft remediation & detection playbooks for Patch Tuesday / out-of-band advisories (deployment, WSUS/Intune/SCCM guidance and best practices).
- Guidance on kernel/EoP hardening and detection strategies — context on how to prioritize and detect post‑exploit behavior.
- Prior examples of “improper link resolution / link following” and local EoP patterns that show recurring classes of risk for maintenance/auto-update or privileged-file-handling components.
- Treat CVE-2025-54116 as a high-priority local-EoP: inventory affected hosts and apply Microsoft’s listed security update(s) as your first order of business. (msrc.microsoft.com)
- If any MultiPoint hosts run in multi-user, classroom, kiosk, or shared environments, accelerate their patching and isolate them from high-value networks until patched.
- Use this disclosure as a prompt to harden local account and application control policies across your estate — EoP bugs are routinely paired with initial access tactics, so making that initial step harder reduces the risk from many vulnerabilities.
- Pull the exact KB number(s) and per‑SKU update mapping for CVE-2025-54116 from MSRC and list the download links and PowerShell commands you can use to deploy and verify those KBs across a ring of machines (I’ll fetch the MSRC/KB mapping and Microsoft Update Catalog entries and include exact commands). (msrc.microsoft.com)
- Produce a short script (PowerShell) you can run in your environment to (a) discover machines with MultiPoint Services installed and (b) check whether the patch KB(s) from Microsoft is present on each host. (I can include safe, copy/paste-ready commands and explain required rights.)
- Draft a Kusto/EDR hunting query tuned for your environment (Microsoft Defender/other EDR) to hunt for likely post‑exploit activity associated with privilege escalation.
Source: MSRC Security Update Guide - Microsoft Security Response Center
